1. Friction Friction is a force that makes things slow down.
Friction acts in the opposite direction of motion.
The rougher the surface, the greater the force of friction.
Smoother surfaces have less friction.
Air resistance occurs when an object moves through the air. (This is how a parachute works!)

2. Study Guide
A ramp has a toy car attached to a rope with weights. What force would be most responsible for the toy car being pulled up the ramp?
Friction
Gravity
Kinetic energy
True or False: In order for a person to lift an object, the upward pull or push on the object must be greater than the force of gravity.
A car moves along a road that has markers every kilometer. Over time, it passes the markers in shorter periods of time. What is happening to the motion of the car? accelerating
A car is traveling at a speed of 70mph to a town 210 miles away. If time = distance divided by speed, how long will the car take to get to town? T= 210 divided by 70 Answer: 3 hours

3. Study Guide - 2
Which of the following is an example of a force being applied?
Two books sitting next to each other on a table
A child reading a book
A dog lying on the ground
A person pulling an apple from a tree
What tool is used to find the direction of a moving object?
Yardstick
Thermometer
Compass
yardstick
Which pair of forces are unbalanced?
A 10N pull North and a 10 N pull South
A 3 N pull North and a 3 N pull East
Which tool(s) would you use to measure the speed of a toy truck? Yardstick, stopwatch
If an apple was falling from a tree, what direction would friction act on the apple?
Up, down, left or right?

4. Study Guide - 3
Causes motion or a change in direction unbalanced forces
Equal forces in opposite directions balanced forces
Tendency of an object to stay in motion inertia
The force of speed of motion momentum
The force that acts on an object to stop its motion friction
A force that pulls all objects toward the center of Earth gravity
A push or pull force
Balanced forces 2. friction 3. inertia
Gravity 5. momentum 6. force
7. Unbalanced forces

5. Study Guide - 4 When you push a grocery cart, you are exerting force.
Two people are each pulling on the opposite ends of a rope. If they are pulling with equal, but opposite forces, what will happen to the rope? Wouldn’t move
What increases as a rock falls to the ground?
Gravity on the rock
Inertia of the rock
Momentum of the rock
A student riding a bike applies the brakes. What helps the bike to stop?
(friction, gravity, heat or momentum)
What would a graph that represents speed
look like?