Definitions
What word means a push or a pull?
Force
To move a heavy object, you need to use a lot of ___________.
Force
How is an object's motion changed?
A force is applied to it.
Give one example of a force changing the motion of an object?
Picking up a book, throwing a ball, pushing a swing, etc.
It can stop a bike, it helps shoes push off the floor to walk, etc.
What are forces that act together on an object without changing it's motion?
Balanced forces
What type of force causes a change in motion?
Unbalanced forces
What will happen to an object you are pushing if you increase the force to make it move?
It will move faster and farther.
What type of force is needed to move a heavy object?
How is friction harmful?
Friction could impact the moving parts in an engine and make it wear out, etc.
What are forces that do not cancel each other out and cause an object to change its motion?
Unbalanced forces
Equal, Opposite
In what two ways can motion be changed by a force?
Speed, Direction
What is the force that occurs when an object rubs against another?
Friction
What types of surfaces typically have the least friction?
Smooth, slippery surfaces
What word means a change in speed and direction over time?
Acceleration
How is an object's motion affected by balanced forces?
It's not affected!
How does force affect the distance an object moves?
How can you increase friction?
By using rough or sticky materials.
Why is friction a contact force?
It occurs between objects that are touching.
What word means a force that opposes the motion of one object moving past another?
Friction
When you apply force, you can change an object's ___________ and ___________.
Speed, Direction
In order to stop motion, you must apply an __________ and __________ force.
Equal, Opposite
What does the force of gravity on an object depend on?
How much mass the objects have and the distance between them.
In what direction does friction act?
In the opposite direction of motion.