Free Body Diagrams
Net Force
Newton's Laws
F=ma
Circular Motion
100
A box hangs from the ceiling. Draw a free body diagram
100
A box is at rest on the table. What is the net force?
0N
100
What is Newton's first law?
An object in motion tends to stay in motion unless acted on by an unbalanced force
100
If a 200kg box is pushed at 10m/s2, what is the force exerted on the box?
2000N
100
What is centripetal force?
The force that holds objects in a circular path
200
A box is pushed across the table, which has friction. Draw the free body diagram
200
A box slides across a frictionless surface with 200N. What is the net force?
200N
200
If Newton's first law says an object in motion wants to stay in motion, why does a rolling ball eventually come to a stop?
Friction is an unbalanced force that opposes the motion
200
A box weighs 100N. What is the mass of the box?
10kg
200
A car is racing around a turn in the track. What force pulls him towards the center of the turn, preventing the car from flying off?
centripetal force
300
A boy pushes a 50N box weighing 100N across a frictionless surface with a force of 20N. Draw the free body diagram
300
A boy pulls a toy car across a surface with 10N. Friction holds it back with 2N. What is the net force?
8N
300
What is Newton's third law?
For every action there is an equal and opposite reaction
300
If a 10kg box is pushed with 100N and friction holds it back with 10N, what is the acceleration?
9m/s2
300
What direction does acceleration point in circular motion?
towards the center of the circle
400
A 6N lantern hangs from the ceiling and does not move. If a boy pushes the lantern with 10N to the right, draw the free body diagram.
400
A rock is tied to a string with 300N in tension. The rock weighs 400N. What is the net force and which way will the rock move?
-100N - down
400
When a bug hits a windshield does it exert the same amount of force on the windshield as the windshield does on the bug? Explain in terms of newton's third law
Newton's third law states that for every action there is an equal but opposite reaction, so yes they are the same force
400
A 100kg box hangs from the ceiling. What is the weight of the box?
1000N
400
Two planets are orbiting each other in space. If the planets drift farther apart over time, what will happen to the gravitational force between them? Explain in terms of the universal law of gravitation
The force will get weaker because objects that are farther apart having a weaker gravitational force (indirect relationship)
500
A box weighing 20N sits on the table. Then, a boy pushes it and friction holds it back. Draw the free body diagram before the boy pushes it, and after
500
Two boys push a box from opposite sides. One boy pushes to the right with 200N. The other boy pushes to the left with 150N. What is the net force? If friction holds the box back with 10N, what will be the new net force?
50N, 40N
500
Why is it hard to keep a ball rolling in a circle (like in the lab?) Use Newton's first law in your answer
An object in motion wants to stay in motion, so the ball wants to keep rolling tangent to the circle. You have to apply an unbalanced force to keep it rolling
500
A box weighs 900N. A boy pushes the box with 100N and friction holds it back with 10N. What is the acceleration of the box?
1m/s2
500
When a ball is swung on a circle, what will happen if the string breaks? What force is pulling the ball in the circle?
Centripetal force, the ball would fly off according to the direction of it's velocity
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