Name: ______Period: ______

Physics Test Force, 9/25/15

Test #2 covers all information since the last test: Friday, 9-11-15, through Friday, 9-25-15. Remember that Physics builds on the skills you have already learned, so you will use all of the information from previous tests on this test. This is a review guide…none of these questions are on the test. You have to understand the skills necessary to answer these questions and apply those skills to the questions on the test. Practice! Take your time.

Topics: Forces, Free Body Diagrams, Newton’s Laws, and Friction

1. Fill in the following table:

Variable / Concept / Units
F
Final Velocity
a / m/s2
Vi
Mass
s
Acceleration due to Gravity

2. State Newton’s First Law of Motion and give an example.

3. State Newton’s Second Law of Motion and give an example.

4. State Newton’s Third Law of Motion and give an example.

5. NEWTON’S EXAMPLES: Which of Newton’s three laws applies – 1, 2, or 3?

_____ A heavier animal has to use more muscles (force) to speed up.

_____ A paddle wheel boat pushes on the water and the water pushes back onto the boat.

_____ Fighter planes feel massive amounts of force when their plane turns quickly.

_____ A rolling ball hits your leg and is hard to stop.

_____ You push on the wall and you don’t move.

6. Define the following terms -

Force (F) -

Net Force (Fnet) –

Weight (Fw) –

Mass (m) –

Inertia –

7. Compare and contrast contact forces and field forces using the Venn diagram. Be sure to include

examples of each.

8. In a vacuum, is a constant force necessary to keep an object moving? Explain______.

9. Draw free body diagrams for each of the following and label using Fg, FN, Fa, Ff, FT

a. a book on a smooth table being pulled rightward with constant velocity

c. a gymnast suspended from the rings

d. a ball free falling

10. Circle the following terms that are vector quantities?

Time Acceleration Mass Force

11. How could friction between two objects be reduced?

12. A 0.500 kg ball with a speed of 4.0 m/s strikes a stationary 1.0 kg target. If momentum is

conserved, what is the total momentum of the ball and target after the collision?

13. TRUE or FALSE? A student on roller skates throws a basketball forward. The product of the

mass times the velocity of the student is equal in magnitude but opposite in direction to the

product of the mass times the velocity of the basketball.

14. Which falls faster a heavy or light object? with air resistance______;

in a vacuum______

*Be sure to use the G.U.E.S.S. method for each problem. Use your equation sheet.

Don’t forget the units in your answers!

15. 35 N is pulling to the left and friction opposes with 15 N. Find the net force

(Remember to show direction.)

16. What is the net force of the box to the right? 20N

40N

17. A 35 kg bike accelerates at 5 m/s2. With what force was the person pedaling?

Given:

Unknown:

Equation:

Substitution:

Solve:

18. If a person is pushing a cart with a force of 9 N and it accelerates 0.5 m/s2,

what is the mass of the cart?

Given:

Unknown:

Equation:

Substitution:

Solve:

19. Find the normal force of a 3 kg mass.

20. What is the mass of a 45 Newton object? Assume that acceleration (due to gravity)

is 9.8 m/s2.

Given:

Unknown:

Equation:

Substitution:

Solve:

21. A car with a mass of 1100 kg is moving down the road at 60 km/h, when it runs out of gas

and coasts to a stop. The wind resistance and road friction total 4300 N.

What is the acceleration of the car

Given:

Unknown:

Equation:

Substitution:

Solve:

22. An object with a mass of 3 kg has a momentum of 75 kg • m/s. What is its velocity?

Given:

Unknown:

Equation:

Substitution:

Solve:

23. A 20 kg child is traveling 3 m/s on an amusement park ride. What is the magnitude of the

child’s momentum?

Given:

Unknown:

Equation:

Substitution:

Solve:

24. Use the diagram to the right to answer the questions that follow:

Which situation(s) show(s) an object on a surface?______

Which situation(s) show(s) an object with balanced forces?______

Which situation(s) show(s) an object with unbalanced forces? _____

Which situation(s) show(s) an object in motion? ______

Which situation(s) shows(s) an object at rest? ______

25. Use the diagram to answer the following questions.

a) The object has a mass of 43 kg.

What is the Force of gravity (weight)?

b) What is the Normal force?