1 of 2

When forces are balanced (equal), the NET FORCE is 0 and there is NO MOTION.

When forces are unbalanced (not equal), the there is MOTION in the direction of the force.

More force on the right side, so the rope will be pulled to the right.

Energy	the ability to do work or cause change
Work	a force acting on an object
Kinetic energy	energy of motion
Net Force	combination of all forces acting on an object
Motion	described as an object’s direction and speed
Speed	how fast an object is moving
Force	any push or pull that causes an object to move, stop, or change direction or speed
Friction	a force that opposes the motion of an object

Unit 3

The Secrets of Force, Motion, and Energy

For use by NNPS Department of Teaching and Learning and families only

2 of 2

Curious Conversations

As we’re walking around or driving, can you spot anything that shows friction, things crashing into each other, or stuff in motion? What do you notice?
What do you think happens when two things bump into each other—like when two cars crash or when you knock over a cup?
When you play tug of war, what’s really going on with the forces? Can you explain it using words like ‘balanced’ and ‘unbalanced’ or ‘net force’?
Have you ever wondered why your desk at school doesn’t just slide around? What keeps it in place?
Let’s say Earth didn’t have gravity for a moment. If you threw a ball into the air, what do you think it would do—keep going up, stop, or fall back down? Why?
How would you describe energy in your own words? And what’s kinetic energy?

When objects collide, the energy from one object transfers to another object.

The energy of the bowling ball is transferred to the pins in this example.

The more mass an object has, the greater the force will need to be to move it.

Objects with the same mass will have greater motion with greater force.

For use by NNPS Department of Teaching and Learning and families only