1. Physics Final Exam Review

2. At what point is the speed of the car the greatest?B B A t

3. At what point is the car accelerating?D C d B A A t

4. While hiking a canyon, you want to determine the height of a cliff
While hiking a canyon, you want to determine the height of a cliff. You drop a rock from the top of the cliff and observe that it takes 5 sec. to reach the ground. How high is the cliff?
Ans.
D=Vot +1/2 a t2
D = 0 + ½ (10)(25) = 125 m.

5. A train is traveling with a velocity of 20m/s north
A train is traveling with a velocity of 20m/s north. If a man walks south in the train at a speed of 3 m/s, what is the man’s velocity with respect to an observer outside the train?
Ans.
20m/s north – 3 m/s south = 17m/s north

6. A parachutist weighs 500N. When his chute opens it pulls the parachutist with a force of 900N upward. The net force on the parachutist after the chute opens is?
400 N upward!

7. With what force F, must a block of mass 50kg be pulled along a horizontal surface with a coefficient of friction equal to .5 to maintain a constant velocity?
245N

8. Friction always acts _____ direction of motion.
In the same B. In the opposite
C. Perpendicular to the
None of the above B.

9. In order to reduce the impact force air bags, rubber bumpers, and piles of hay:_______.
Expand B. Decrease the time of interaction
C. Increase the time of reaction D. Contract C.

10. A. 5kg baseball is coming at a batter at 35m/s
A .5kg baseball is coming at a batter at 35m/s. The ball leaves the bat at 40m/s.
A. What is the Δp?
Δp = pf – pi
Δp = .5(-40) - .5(35)
Δp = kgm/s

11. If the previous problem had the bat in contact with the ball for
If the previous problem had the bat in contact with the ball for .05s, what force is exerted on the ball?
Ft = mΔv
F (.05) = 37.5
F = 750 N

12. While on Earth, we have weight
While on Earth, we have weight. If Earth’s mass suddenly tripled, what would happen to our weight? It would:
A . Triple
B. Double
C. Be 1/3
D. Be ½ A

13. In order to cause a moving object to pursue a circular path, it is necessary to apply a(n)_____.
A. Intertial force B. Gravitational force
C. Frictional force D. Centripetal Force E. Centrifugal Force D.

14. Where on the path is the potential energy the greatest?B C
Where on the path is the potential energy the greatest? A
Remember that the speed at C can be found by setting PE = KE!

15. What kind of energy does the car have at point B?
Potential energy B. Kinetic Energy C. Both A &B D. No Energy at all C.

16. If the height of the ride is 20m, what is the speed at point C?B C
If the height of the ride is 20m, what is the speed at point C?
20m/s b. 196m/s c. 392m/s d. cannot tell
a. 20m/s

17. An elastic collision is one in which the objects:
A. Collide at angles B. Collide at different speeds C. Stick together D. Bounce off each other D.

18. In a horizontal projectile, the ________ velocity is a constant.
a. Horizontal b. Vertical c. Angle d. None of these
Answer: a

19. What is the optimal angle for a projectile to go the farthest horizontal distance?
a. 30 degrees b. 45 degrees c. 60 degrees d. 90 degrees
Answer: b

20. c a b
Which arrow designates tangential velocity?
Answer: a

21. A vector quantity has:
Magnitude and time
Magnitude and direction
Direction and time
Time, direction and magnitude
Answer: a