Force

You can refer to the activities enlisted in this module to introduce, revise and clear concepts regarding the topic force by using gamification, Hands on Experiments & inquiry method

Activity 1

Tug of War Activity

Determine the relation between balanced or unbalanced forces and the state of motion of an object

Class - 8th

Time - 15 mins

Gamification

Activity 2

Activity 3

Conservation of Momentum

Build observational and investigative skills

Class 9th

Time - 20 mins

Critical Thinking

Balloon Rocket !

By experimenting with varying net force and mass, and measuring resulting accelerations, one can uncover their interrelationships; additionally, kinematic equations aid in predicting acceleration changes due to alterations in net force or mass, fostering observational and investigative skills.

Class - 9th

Time - 40 mins

Experimentation & Verification, Hands on

Exploring Forces & their Effects

Observe and understand how different forces affect an object's motion, direction, speed, and shape.

4o

​

Class 9th

Time - 15 mins

Inquiry

Activity 6

Activity 7

Activity 8

Activity 1 1:

Tug of War Activity !

• Ask each group to apply equal force to the rope in opposite directions, ensuring that the center of the rope remains above the marked line.
• Encourage the rest of the class to observe what happens when the forces are applied and how the rope behaves Facilitate a discussion on balanced forces, asking questions such as:
• What did you observe when both groups applied equal force to the rope?
• Why did the center of the rope stay above the marked line?
• What happens when the forces are unbalanced?

Challenge:

• Now, challenge the groups to see which group can pull the rope and the other group towards them.
• Discuss the concept of unbalanced forces and its effects on motion.
• What happens if one group applies more force than the other?
• How can you ensure that the forces applied by both groups are equal?
• What do you think would happen if the rope were replaced with a heavier or lighter object?

​

​

​

To understand the concept of balanced forces and to observe how forces interact in a practical scenario.

Materials Needed:

Soft rope,Marker or chalk to mark the center and line of division,Participants (students)

Prior knowledge:

Students should know the concepts of Forces, Push, Pull.

Procedure:

• Choose an open area in the classroom or outside where the activity can be conducted safely.
• Mark the center of the rope and a line perpendicular to it to indicate the division point.
• Gather all participants and explain the rules and safety precautions.
• Divide the participants into two equal groups.
• Place the rope on the ground with the center aligned with the marked line of division.
• Instruct both groups to stand on either side of the rope.
• Tips: Use a soft rope to avoid hurting anyone during tug of war.

.

​

​

​

​

Inquiry probe questions:

• What would happen if one group suddenly stopped pulling while the other continued? Why?
• Can you relate this to how objects accelerate or change direction in real life?
• How might the results have differed if we used a heavier or lighter rope?
• Can you think of any real-world situations where balanced forces are important for stability or equilibrium?
• Can you give an example where unbalanced forces are necessary?
• If you were to design an experiment to test the effects of different surfaces on the rope's stability, what variables would you consider?
• What role do you think friction played in this activity, if any?
• How might you modify this activity to investigate the effects of changing the angle of the rope or the distance between the groups?
• What would happen if a third force was applied in a different direction?

​

​

​

​

Link:

https://phet.colorado.edu/sims/html/forces-and-motion-basics/latest/forces-and-motion-basics_all.html

Misconceptions:

• Students might think that the stronger group will always win. Emphasize that it's not just about strength but also about the balance of forces.

​

Innovation corner:

After the activity, task students with designing and testing a system (such as a pulley or lever) that could either balance or unbalance the forces more efficiently. This will integrate engineering principles into their understanding of forces.

History of the Tug of War activity

Cross Topics :

Tug of war, with ancient roots seen in civilizations like Egypt and China, evolved into a popular medieval pastime, gained formal rules in 19th-century Britain, and briefly featured in the Olympics (1900-1920) before declining as a competitive sport. Today, it remains a recreational activity worldwide.

​

​

​

​

​

​

​

​

What is the Balanced Forces?

​

​

​

​

​

​

​

​

If two friends are playing tug of war with same strength, they pull the rope equally in opposite direction and because of this rope stays in middle not moving

F1 = F2

​

​

What is Net Forces?

​

​

​

​

​

​

​

The net force is like the combined effect of pushing or pulling on an object. Imagine two friends pushing an object – one pushes to the right, and the other pushes to the left. The net force is what happens when you add up all these pushes. If another friend joins and pushes to the right, the combined push from the right becomes stronger, making the object move in that direction. If more friends push to the left, the object moves left. However, if everyone pushes equally in all directions, the forces balance each other out, and the net force becomes zero

​

​

​

​

​

​

​

​

​

​

​

​

Activity 2 2:

​

Active Learning: Force in Action

To help students understand the concept of force by engaging in hands-on activities that involve pushing and pulling objects.

Material: tennis balls or soft rubber balls)

Doors or windows that can be easily opened and closed

Prior knowledge:Students should have a basic understanding that objects can be in motion or at rest.

Procedure:

• Begin by discussing the concept of force and its role in the motion of objects.
• Explain that force can be applied through pushing or pulling.
• Arrange the classroom space to allow for the activities like throwing a ball towards a wall, stopping a moving ball, opening a door/window, and closing a door/window.
• Divide the students into small groups or pairs.
• Guide the students through each activity one by one, allowing them to perform and observe.
• For example:
• Activity 1: Instruct students to set a stationary ball in motion by throwing it towards a wall.
• Activity 2: Have students stop a moving ball by applying force with their hands or bodies.
• Activity 3: Ask students to open a door or window by pushing or pulling on it.
• Activity 4: Similarly, have students close the door or window.

​

​

​

​

• After completing the activities, gather the students for a discussion.
• Ask questions to guide their understanding, such as
• What did you do while throwing the ball?
• How did you stop the moving ball?
• Did you feel a pull on your hand while opening or closing the door/window?

Probing Questions:

• What did you observe while performing each activity?
• How did you apply force to move or stop the objects?
• Can you describe the direction of the force in each activity?
• Did you notice any differences in the force required for different activities?
• How did your actions demonstrate the concept of force?
• Can you think of any other examples of everyday actions that involve applying force?

​

​

​

​

​

​

​

​

​

​

​

​

​

Innovation corner:

• Encourage students to come up with creative variations of the activities, such as using different types of balls or experimenting with various surfaces for throwing.
• Challenge them to explore the effects of applying force at different angles or strengths in each activity.
• Incorporating Variable Forces:�Let students experiment with different surface types (e.g., carpet vs. smooth floor) to understand friction and how it affects the force required to move an object. This allows a deeper exploration into how environmental factors influence force.
• Force and Motion Simulation:�If available, use online simulations of force and motion (such as PhET simulations) where students can manipulate variables like mass, force, and friction to observe different outcomes. This helps visualize more complex scenarios that are hard to replicate in the classroom.

​

​

Misconceptions:

• Students might believe that larger objects always require more force to move, without considering the role of friction or balanced forces acting on smaller objects.
• Some students may think that force is not present when an object is stationary, neglecting the idea of balanced forces acting on the object to keep it at rest.
• Force is Only Needed to Start Motion:�Students may think that force is only necessary to get an object moving and not to maintain or stop the motion. It's important to clarify that forces like friction and air resistance act on moving objects, requiring continued force to maintain motion or stop it.
• Force Only Works in One Direction:�Students may mistakenly believe that force is only applied in the direction of motion (e.g., thinking pushing a door is only in one direction). The concept of opposing forces, like friction or resistance, can help them understand that forces act in multiple directions.

​

Activity 3:

Explore Static electricity with paper rotation experiment

The aim is to demonstrate the effect of static force on the rotation of paper.

Material: Paper cup,Pencil,Bend straw,Tissue paper,Rectangular piece of paper

Prior Knowledge:

Static Electricity, Electric Charge, Attraction & Repulsion of charges, Friction, Forces & motion, Conductors & Insulators.

​

Procedure:

• Make a hole at the bottom of the paper cup.
• Insert the pencil through the hole to create a stand for the cup.

​

• Take a rectangular piece of paper and fold it to mark the center.

​

​

​

​

​

​

• Place the paper on top of the pencil stand.
• Rub the bend straw with a tissue paper to create static electricity.

​

​

​

​

​

​

​

​

​

​

​

• Bring the rubbed straw near one end of the paper and observe the movement of the paper.

​

​

​

• ​
• ​
• ​
• ​
• ​

​

​

​

• As you rotate the straw, notice how the paper rotates in response to the static electricity.

​

​

​

​

​

​

​

​

​

​

​

​

​

Inquiry probe questions:

​

• What happens when you rub the straw with the tissue paper?
• Why do you think the paper rotates when you bring the rubbed straw near it?
• What type of charge builds up on the straw after rubbing it with tissue paper?
• Negative charge (due to the transfer of electrons).
• Why does the paper respond to the charged straw when you bring it close?
• The paper is attracted to the opposite charge on the straw.
• How does the movement of the paper confirm the effects of static electricity?

​

​

Innovation corner:

Different Materials:�Experiment with various materials (e.g., different types of paper, plastic sheets, or aluminum foil) to observe how their properties affect the interaction with static electricity and the movement of the paper. This can lead to discussions about conductors and insulators.

Digital Data Collection:�Implement a data collection method using sensors or video recording to analyze the rotation speed and distance of the paper. This can help students quantify the effects of static electricity more effectively.

Integration of Technology:�Use a slow-motion camera to record the interaction. Students can analyze the video to observe the subtleties in the motion of the paper in response to the static force applied by the straw.

Exploring Environmental Factors:�Investigate how humidity affects static electricity by performing the activity under different humidity levels. Students can measure and discuss the variations in the static charge's effectiveness based on environmental conditions.

Extension Activities:�Follow up with a discussion or activity on how static electricity is used in real-world applications, such as in photocopiers, printers, or even lightning. This will help contextualize the concept beyond the classroom.

​

​

Misconceptions:

A common misconception might be that static electricity only occurs with certain materials or in specific conditions. This activity helps dispel this by showing that static electricity can be generated and observed with simple materials in a classroom setting.

Activity 4:

Paper Strip Helicopter Experiment

To demonstrate the gravitational force

Materials:

12 cm x 3 cm paper strip,scissors

Prior Knowledge:Students should understand gravity as a force that pulls objects toward Earth.

Procedure:

• Provide each student with a paper strip and a pair of scissors.
• Instruct students to mark the paper strip as shown in the figure.

​

​

​

​

​

​

• Guide them to carefully cut along the markings to create the required shape.
• Demonstrate and explain the folding process as shown in the figure.

​

​

​

​

​

​

​

​

​

• Encourage students to fold their paper strips accordingly to create the helicopter shape.

​

​

​

​

​

​

​

​

​

​

​

• Once the helicopters are folded, instruct students to hold them as high as possible.
• Ask them to release the helicopters and observe their descent.
• After the helicopters have been released, lead a discussion on what students observed.
• Ask probing questions such as:
• What happened when you released the helicopter?
• Did the helicopter fall straight down or did it spin?
• Why do you think the helicopter spun as it fell?
• How do you think the shape of the helicopter affects its descent?

​

​

​

​

​

​

Probing Questions:

• How did the shape of the paper strip change as you folded it into a helicopter?
• Why do you think the helicopter spins as it falls?
• What forces do you think are acting on the helicopter as it descends?
• How could you modify the design of the helicopter to change its flight characteristics?
• Can you think of any real-life applications of this concept?
• What happens if we use different sizes and smoother, harder paper to make the paper helicopter?

​

​

​

Effects of Gravity on paper Helicopter:-

• Downward Pull: Gravity pulls the paper helicopter downward, accelerating it initially.
• Steady Descent: Gravity increases the speed of descent, but air friction slows it down.
• Learning Outcome: Gravity ensures that the helicopter falls, affecting all objects with mass equally.

Effects on Air friction on paper helicopter:-

• Opposing Force: Air friction opposes gravity, slowing the helicopter's descent.
• Rotation: The spinning blades increase air resistance, controlling the fall.
• Steady Descent: The interaction between rotation and air friction stabilizes the descent, creating a spiral motion.

​

Innovation corner:

Encourage students to experiment with different shapes and sizes of paper strips to see how they affect the helicopter's flight.

​

Relate this to real-life helicopters or wind turbines, prompting students to think of other applications for rotational force in technology.

​

​

Misconceptions:

• Students might think that the helicopter spins due to an external force, rather than understanding that it's caused by air resistance interacting with the shape of the paper.
• Some students may believe that all objects fall straight down, rather than understanding that the shape and surface area of an object can affect its descent.

​

Activity 5:

Exploring Friction with Inclined Planes

​

The aim is to observe and understand how friction affects the movement of objects on inclined surfaces.

Material: Cardboard or smooth surface

Blocks (at least two),Aluminum foil

Prior Knowledge:

Gravity: Its role in pulling objects downward.

Procedure:

• Place a cardboard or any smooth surface on a flat table.
• Put a block on the cardboard.
• Slightly raise one end of the cardboard and observe the block. Note that it stays in place due to static friction.
• Increase the inclination gradually and observe how the block starts to slide down slowly due to the force of gravity overcoming static friction.

​

​

• Further increase the inclination to observe the block sliding down rapidly, indicating reduced friction.
• Cover another block with aluminum foil.
• Repeat above step with the foil-covered block and compare the sliding speeds with the previous observations.

​

​

​

​

​

​

​

• Begin by introducing the concept of friction and its effects on objects' movement.
• Present the materials and demonstrate each step of the experiment, encouraging students to make observations.
• Engage students with questions:
• Why does the block stay in place initially?
• What factors influence the speed of the block sliding down?
• How does covering the block with aluminum foil affect its movement?

​

​

​

​

​

​

​

​

​

Inquiry probe questions:

• What did you observe when we gradually increased the inclination of the cardboard?
• How did the block's movement change as we altered the angle of the surface?
• Can you explain why the block initially stayed in place when we slightly raised the cardboard?
• What factors do you think determine the amount of friction between the block and the surface?
• How did the movement of the block covered in aluminum foil differ from the uncovered block?
• Why do you think there was a difference in their sliding speeds?
• Can you think of situations in daily life where understanding friction on inclined surfaces is important?
• How might engineers or designers use this knowledge to improve the functionality of objects or structures?
• What other variables could we change in this experiment to explore the effects on friction further?
• How would you design a follow-up experiment to investigate the relationship between surface texture and friction?
• How does the concept of friction apply to scenarios beyond the movement of blocks on inclined surfaces?
• Can you think of examples where reducing friction is desirable, and how might this be achieved?
• what will happen if the material of paper is changed rough/ smooth/glossy?

​

​

​

​

Innovation corner:

Encourage students to explore how changing the texture of the surface affects friction. For example, they can test surfaces with sandpaper or felt instead of cardboard.

​

​

​

Misconceptions:

One common misconception might be that all surfaces have the same amount of friction. This activity helps to dispel this by demonstrating how different surfaces and inclinations affect friction.

​

Activity 6:

Exploring Muscular Force and Contact Forces

The aim is to understand the concept of contact forces by engaging in physical actions and experiencing muscular force.

Material: Water bottles, Football

Prior Knowledge:

​

​

Procedure:

Activity 1: Lifting a Water Bottle:

• Each student will lift a water bottle from the table.
• While lifting, students should pay attention to the force exerted by their muscles.

​

​

​

​

​

​

​

​

​

​

​

​

​

​

​

​

Activity 2: Kicking a Ball:

• Students will kick a ball placed on the ground.
• They should observe the force exerted by their leg muscles during the action.

​

​

​

​

​

​

​

​

​

​

• Demonstrate each activity and ensure students understand the physical actions involved.
• Encourage students to perform the activities individually or in pairs.
• After each activity, discuss students' experiences with muscular force and how it relates to contact forces.
• How did it feel to lift the water bottle or kick the ball?
• What muscles did you use, and how did they exert force during the actions?
• How do these physical actions demonstrate contact forces in everyday life?

​

​

​

​

​

Inquiry probe questions:

​

• What do you understand by muscular force, and how is it different from other types of forces?
• How can we investigate the impact of friction (a contact force) on the speed of a rolling object?
• What happens to an object when the muscular force applied is greater than the opposing contact forces?
• Can you share a personal experience where you had to apply muscular force to overcome a challenge?

​

Innovation corner:

​

Robotics has introduced exciting new devices called exoskeletons. These devices help people with mobility challenges by providing extra support and strength. They use mechanical systems to boost a person's muscular force, making it easier for them to move. This shows how contact forces can be used in real life to improve physical abilities.

​

​

​

Misconceptions:

One common misconception might be that force is only exerted when objects are moved. This activity helps dispel this by showing that force is exerted even when objects are stationary or undergo changes in motion.

Activity 7:

Exploring Forces and Their Effects

The aim of this activity is to observe and understand the effects of different forces on objects, including changes in motion, direction, speed, and shape.

Material:

Printout of the table listing situations and changes in states Objects such as balls, balloons, clay

Carrom board, bat, cricket ball, etc.

Prior Knowledge:

Forces and their types (e.g., gravitational force, friction)

Procedure:

• Begin by discussing with the students the concept of forces and their effects on objects. Explain the different types of forces such as gravitational force, friction, applied force, etc. Discuss how these forces can cause changes in the state of motion, direction, speed, and shape of objects.
• Provide the students with a set of situations listed in the table. Explain each situation briefly, emphasizing the forces involved and the expected changes in the objects' states.

​

• Divide the students into groups and assign each group one or more situations from the table. In their groups, students should perform the given situations and observe the changes in the objects' states.
• As the students perform each situation, they should record their observations in the provided table. They should note down any changes in motion, direction or speed, and changes in shape for each situation.
• After performing the activities, reconvene as a class to discuss the observations made by each group. Encourage students to explain the effects of different forces on the objects in each situation. Address any questions or misconceptions that arise during the discussion.

​

​

​

​

​

​

​

​

​

​

​

​

​

Inquiry probe questions:

• What forces are acting on the objects in each situation?
• How do these forces cause changes in the objects' states?
• Can you identify any patterns or similarities in the effects of different forces?

Misconceptions:

All objects fall at the same rate regardless of their mass.

The force of friction always opposes motion.

Objects in motion will continue moving forever unless acted upon by a force

Innovation corner:

​

​

​

​

​

Activity 8:

• Use cello tape to stick the balloon horizontally to the straw.

Balloon Rocket Experiment: Exploring Newton's Laws

​

The aim of the above activity is to demonstrate and explore Newton's laws of motion through the construction and observation of a balloon rocket experiment.

Material:

Balloons, one paper straw/ empty pen-body, cello-tape, string (3- 4 m long), known weight/s (a set of coins or washers), stopwatch/ smart-phone

Prior knowledge:

Force, Balanced & Unbalanced Force

Procedure:

Form groups of 3-4 students.

• Provide materials to students for balloon rocket construction.
• Allow for various rocket designs, fostering innovation, even if some may be unconventional.
• Tie one end of a string to a fixed support like a table or doorknob.
• Thread the other end of the string through a straw.
• Pull the string tight and tie the loose end to another support.
• Blow up the balloon and pinch the open end without tying a knot.

​

• Assign roles within each group (e.g., balloon inflator, timer, recorder).
• Each group conducts the experiment by releasing the balloon and timing its motion along the string using the stopwatch or smartphone.
• Ensure students observe and record the distance traveled by the balloon and the time taken for the journey.
• First Law (Law of Inertia): Discuss how the balloon rocket remains at rest until an external force (the released air) is applied, initiating its motion. Emphasize the concept of inertia and the need for an unbalanced force to change the balloon's state of motion.

​

​

​

​

​

​

​

​

• Second Law (Law of Acceleration): Introduce the idea that the acceleration of the balloon rocket depends on the net force acting on it (resulting from the expulsion of air) and its mass. Discuss how the balloon's mass affects its acceleration when the same force is applied.
• Third Law (Action-Reaction): Explain how the expelled air exerts a force backward, propelling the balloon rocket forward. Emphasize the equal and opposite reaction between the air escaping from the balloon and the forward motion of the rocket.

​

​

Innovation corner:

• Space Exploration
• Engineering Design
• Try to link it with Chandrayaan & mars mission

Cross Topics :

• Astronomy
• Mathematics

​

​

​

​

​

Inquiry probes:

• What will happen if the masses attached to the balloon are changed and the circumference of the balloon is kept constant? 
• What do you think will be the effect on motion of the balloon rocket if the mass attached to it is increased to twice the original?
• How did the mass of the balloon affect its acceleration?
• Can you explain why the balloon rocket moved in the direction opposite to the expelled air?
• Did the length of the string have any noticeable impact on the motion of the balloon rocket? If so, how?

​

Possible misconceptions:

• Rocket needs air to move
• Big rocket can go in higher distance

Activity 9:

• Ask students to describe what they observe.
• Why do you think only the marble at the opposite end moves?
• Discuss the concept of conservation of momentum and how it applies to this activity.

​

• Change the mass by displacing two marbles at a time.
• Note down the observations.
• Ask students to predict what will happen before conducting each trial.
• What do you expect to happen when we change the mass?
• Conduct the trials and discuss the results.
• Why do you think only the marble at the opposite end moves, while the ones in between stay still?
• Try pulling and releasing three marbles at the same time.
• Note down the observations.
• Ask students to predict what will happen.

​

Conservation of Momentum with Marbles

​

​

The aim of the activity is to demonstrate and understand the principles of conservation of momentum and impulse using a simple Newton's Cradle setup with marbles.

Materials:

Marbles of the same as well as different sizes,Thread,two types of m-seal to make adhesive,a strong and stable vertical support to hang the marbles and threads

Prior knowledge:

Momentum, Scalar vector quantities, Newton’s Laws of Motion,

Procedure:

• Prepare the adhesive by mixing the two types of m-seal.
• Cut pieces of thread and tie one to each marble using the adhesive. Ensure the lengths are adjusted so the marbles will align horizontally.
• Hang the threads from the vertical support structure.
• Make sure the marbles are touching each other and aligned horizontally.
• Adjust the lengths of the threads if needed to keep the alignment.
• Pull a marble away from one end of the line and let go. Observe the motion of the other marbles.

​

​

​

​

​

• How do you think pulling three marbles at once will affect the motion compared to pulling just one?
• Conduct the trial and discuss the results.
• Can you explain why the middle marble remains still?
• Summarize the key concepts learned during the activity.

Inquiry probe questions:

• What did you observe when you pulled and released a marble from one end?
• Can you explain why only the marble at the opposite end moved while the others remained still?
• How did changing the mass by displacing two marbles at a time affect the motion compared to pulling just one?
• Why do you think the middle marbles remained still when we changed the mass?
• can you predict what would happen if we changed other variables, like the angle of release or the elasticity of the marbles?
• How might friction or air resistance affect the results, and how could we account for these factors?

​

Innovation corner:

• Encourage students to design their own experiment for conservation of momentum.

​

Cross Topics :

Sport

​

​

Possible misconceptions:

​

​

​

​

​

​

​

​

​

• We will use this Newton's cradle to understand the concept of momentum and conservation of it. Grab a marble and pull it onwards.
• Releasing the marble will make the marble from the other side move almost equal distance outwards. Make sure that there is no space in the marbles or the collision will not be elastic.

​

​

​

​

​

​

• Now we will change mass by displacing two marbles at a time. Pull two marbles outwards.
• As the marbles hit other marbles, two marbles will on the other side will move outwards to approximately same distance.

​

​

​

​

​

​

​

​

​

​

​

​