What is the difference between speed and velocity?
Velocity has direction.
100
What force opposes motion?
Friction
100
What is inertia?
The tendency to resist change in motion.
100
What are the two things that momentum depends on?
Mass and Velocity.
100
Give an example of a machine that only changes the direction of a force.
Fixed Pulley
200
What is negative acceleration?
A decrease in velocity, or deceleration.
200
Give an example of a balanced force and an unbalanced force.
Sitting in a chair and kicking a ball.
200
Which law says that acceleration decreases as mass increases?
Newton's Second Law
200
If a car and a bus are traveling at the same speed, which has more momentum and why?
The bus because it has more mass.
200
Give an example of a machine that decreases the force.
Third Class Lever
300
What is the constant velocity an object reaches when air resistance equals gravity?
Terminal Velocity
300
Define mass and weight in your own words. Which of the two can change?
Mass is how much matter is in an object. Weight is how much gravity pulls on an object. Weight changes with gravity.
300
Which law says that for every action force there is a reaction force?
Newton's Third Law
300
Car A is 2000 kg and traveling west at 30 m/s. Car B is 3000 kg and traveling east at 20 m/s. If they stick together when they crash, what is their velocity after the crash?
0 m/s
300
Why do compound machines have more friction?
They have more moving parts.
400
What type of acceleration do you have when traveling at a constant speed? Describe what happens.
Centripetal Acceleration - traveling in a circular motion
400
If one student pulls a box with 22N east and another student pushes the box with 22N east, what is the net force?
44 N East
400
Which law says that force equals mass times acceleration?
Newton's Second Law
400
What is the Law of Conservation of Momentum?
The total amount of momentum stays the same after a crash.
400
What are the two things a machine can do?
Change the size or direction of a force.
500
What are the two parts of projectile motion? Which of the two remains constant?
Vertical and Horizontal. Horizontal remains constant.
500
What are three ways to reduce friction? Give an example when you could use each one.
Make the surface smoother - using sandpaper on a bench. Adding wheels - moving furniture. Using a lubricant - bike chain
500
What is Newton's First Law?
An object in motion will stay in motion and an object at rest will stay at rest unless an unbalanced force acts on it.
500
Newton's Third Law says that for every action there is a reaction. How is this related to the law of conservation of momentum?
Because action and reaction forces are equal and opposite, no momentum is gained or lost.
500
List the six simple machines and give an example of each.
Lever, Inclined Plane, Wedge, Screw, Pulley, and Wheel & Axle.