Name: ______Date:______Group Members: ______

Newton’s Laws Review

1)  We have learned that all objects obey Newton’s First Law of Motion whether at rest or in motion. What does Newton’s first Law tell us about objects at rest? ______

2)  What does Newton’s first Law tell us about objects at rest? ______

3)  According to Newton's First Law what happens to an object when an unbalanced force is applied, in other words Fnet doesn’t equal zero. ______

4)  What have we done in class to prove this is correct? ______

In questions #5-8 you are standing, facing forward on a bus. How do you have to brace yourself (the seat in front or behind) if the bus is... and Why…

5)  at rest? ______

6)  moving forward at a constant speed? ______

7)  moving forward and speeding up? ______

8)  moving forward and braking? ______

In questions #9-12 you are standing, facing forward on a bus. You are holding a pen immediately to the right of your right shoulder. You drop the pen. Where will the object land if the bus is... Why…

9)  at rest? ______

10) moving forward at a constant speed? ______

11) moving forward and speeding up? ______

12) moving forward and braking? ______

What is the unbalanced force (Fnet) on each of the blocks shown below (tell me Fnet horizontal and Fnet vertical)?

11.
Fnet x = 10N + -8N = 2 N / 12.
Fnet x =
13.
Fnet x = / 14.
Fnet x =
15.
Fnet y = 55N + -25N = 30 N / 16.
Fnet y =
17.
Fnet x =
Fnet y = / 18.
Fnet x =
Fnet y =
19. A book weighing 16 newtons sits on a table. On the drawing to the right draw and label the forces acting on the book. Do this as it was taught to you in class. Hint: one up and one down.
20. The same book shown in #17 above has a person pushing down on it with a force of 25 newtons. On the drawing to the right draw and label the forces acting on the book. Hint, there are three forces here and the sum of the forces adds up to zero.
21. A large crate is being pushed to the right by a force of 200 newtons. The box weighs 950 newtons and moves at a constant speed. Hint, there are four forces here and the sum of the forces adds up to zero.

Newton's Second Law of Motion

1. If there is an unbalanced force acting on an object, what happens to the object? ______

In what direction will the object accelerate in respect to the direction of the net force? ______

What did we do in class to demonstrate this? ______

______

2. A student pushes on a 50 kilogram wagon so that is accelerates at 2.0 m/s2. What force did the student apply to the wagon? Make a score card!!!!!

Mass = ______

Acceleration = ______

Force = ______x______= ______x______= ______

3. A woman pushes on a 40 kilogram object with an unbalanced force of 20 newtons. What will be the acceleration of the object? Make a score card!!!!!

4. A man pushes on a crate in the direction shown. Friction acts on the crate to the right as shown. If the crate is already moving to the left, will it speed up, slow down, or stay at the same speed if the man pushes with a force of...
60 N? ______
50 N? ______
75 N? ______
5.  The box at the right has a mass of 1.0 kilogram.
-  Fnetx =
-  Using a score card find the acceleration.

6. A man pushes on a crate with a force of 100 newtons East against a force of friction of 60 newtons. The crate has a mass of 100 kilograms.

a.  Make a free body diagram of the box.

b.  What is the net force on the box?

c.  What will be the acceleration of the crate?

By showing all the forces acting on the block, draw an arrow to show the direction of the force, identify the force, and indicate the magnitude of the force.

7. The force of gravity on block A is 5.0 newtons. / Draw a FBD of just Block A, include numbers for the force of gravity and normal force. Hint:
Weight= force due to gravity= mass x gravity (10m/s2) and since a = zero then Fnety = 0
8. The weight of block A is 5.0 newtons and the applied force (FA) is 1.5 newtons. Block A is at rest, a = zero and Fnet = 0 . / Draw a picture of just Block A and show all the forces acting on the block.
9. The weight of block A is 8.0 newtons and the applied force (FA) is 1.4 newtons. Block A is moving to the left with a constant velocity. / If the block moves at a constant velocity
Fnet =
Acceleration =
Draw a picture of just Block A and show all the forces acting on the block.
10. The weight of block A is 10.0 newtons and the applied force (FA) is 2.0 newtons. Block A is speeding up as it moves to the left. / If the box is speeding up what does that mean about:
Acceleration:
Fnet :
The forces acting right vs. left:
Draw a picture of just Block A and show all the forces acting on the block.
11. The weight of block A is 10.0 newtons and the applied force (FA) is 2.0 newtons. Block A is slowing down as it moves to the left. / Draw a picture of just Block A and show all the forces acting on the block.
12. The weight of block A is 15.0 newtons and the system is static. Static means, “not moving”. / Draw a picture of just Block A and show all the forces acting on the block.
13. The weight of block A is 5.0 newtons, the weight of block B is 3.0 newtons, and the system is static. / Draw a picture of just Block A and show all the forces acting on the block.
Draw a picture of just Block B and show all the forces acting on the block.

Sports: Chapter 2 - Analyzing the Forces on an Object page 8 7/30/2013