1. Quiz Review

2. In an oscillating spring, where is the maximum acceleration achieved?

3. Answer: At the maximum displacement positions

4. When the spring is stretched and released, what direction does the spring force act?

5. Toward the equilibrium position

6. When the spring is stretched and released, when is speed equal to 0?

7. Answer: at the point of maximum displacement.

8. Often, the negative sign in Hooke’s Law is ignored
Often, the negative sign in Hooke’s Law is ignored Why is this possible?

9. Answer: because the sign indicates that the force and displacement are in opposite direcitons

10. What are the units for k?

11. Answer: N/m

12. When using Hooke’s Law, what units does the displacement value need to be in?

13. Answer: meters

14. In an oscillating system, where is the greatest kinetic energy located?

15. Answer: At the equilibrium positon

16. If the mass of a pendulum cut in half, what happens to the period?

17. Answer: no change, mass does not affect the period of a pendulum

18. If the length of a pendulum is increased by 16 times, what happens to the period?

19. Answer: increases 4 times longer

20. If a pendulum clock keeps perfect time at the base of a mountain, will it also keep perfect time when moved to the top of the mountain? Why.

21. No, the gravity is slightly different so the period will change also

22. The moon’s gravity is 1/6 of Earth
The moon’s gravity is 1/6 of Earth. If a mass spring system with a mass of 2 kg has a period of 3 sec on Earth, what will be the period on the moon?

23. 3 sec, gravity does not affect mass-spring systems.

24. If you know the cycles and time, how do you find frequency?

25. Cycles divided by sec

26. Given period, how do you find frequency?

27. 1 divided by the period, they are recipricals

28. If a grandfather clock is running slow, how can you adjust the length of the pendulum to correct the time?

29. Shorten the length to shorten the period

30. Problems

31. If a force of 50 N stretches a spring
If a force of 50 N stretches a spring .10 m, what is the spring constant?

32. 500 N/m

33. A mass on a spring vibrates in simple harmonic motion at an amplitude of 8.0 cm. If the mass of the object is .20 kg and the spring constant is 130 N/m, what is the frequency?

34. 4.0 Hz

35. On the planet Xenos, an astronaut observes that a 1
On the planet Xenos, an astronaut observes that a 1.00 m long pendulum has a period of 1.50 s. What is the free-fall acceleration on Xenos?

36. 17.5 m/s2

37. A pendulum goes past the equilibrium position once every 2 seconds, what is frequency of the pendulum?

38. .25 Hz