Reading Quiz

Question 1:

Answer:

1. The period of a pendulum for low amplitude swings depends on its stiffness (how stiffly restoring forces push it back and forth) and on the resistance of its mass to back and forth motion (a larger mass would have a larger period because it resists the motion more). Both factors are affected by the length of the pendulum and the force exerted by gravity. A pendulum that would take 4s to complete a cycle near the surface of the earth would be 3.98m long, so about 4m.
2. The length of the pendulum and the strength of gravity. You can solve for the length of the pendulum when you know the desired period and strength of gravity. That would be about 24 meters
3. The length of the pendulum and the acceleration due to gravity determines the period of a pendulum. 4= 2*pi*(x/9.8)^.5 ==> x = 3.97. Thus I would design a pendulum with length of 4 m.
4. period of pendulum= 2pi[(square root)length of pendulm/ acceleration due to gravity]. You would need a pendulum with a 3.97 meter length.
5. Besides the acceleration due to gravity, the only thing that impacts the period of a pendulum is its length. If you wanted a pendulum whose period would be four seconds, you could use the formula period=2pi times the square root of the length of the pendulum over the acceleration due to gravity, and find that the length of the pendulum would have to be 3.98 meters.
6. The length of the pendulum and the acceleration due to gravity determine the period of a pendulum. In oder to have a pendulum that would take 4s to complete a cycle, the lenth of the pendulum would have to be very long. Using the formula, the length would be 3.972m.
7. a pendulum's period is affected by length of the pendulum and acceleration due to gravity. Near the earth, a pendulum with a cycle of 4 s would need to have a pendulum length of about 4 meters.
8. The period is determined by the magnitude of the restoring force pushing it back and forth and how stubbornly the mass resists this force. A pendulum that was 160 inches long would take 4s to complete a cycle.
9. The length of the pendulum and the pendulum's accelearation due to gravity is what affects it's period. To design one that would take 4s you could use any mass attached to a pendulum that was about 3.93m long, and that should have a period of about 4s.
10. The period of a Pendulum is determined by how stiffy its restoring force pushes it back and forth and how its mass resists the back and forth motion. Have a harmonic oscillator with loose resisting forces and large masses.
11. The period of a pendulum depends on the pendulum's length and on gravity. Since a 40inch pendulum takes 2seconds to complete its cycle, if we made an 80inch pendulum, it should take 4 seconds to complete a cycle.
12. The period of a pendulum depends on both the stiffness of its restoring force and on its mass. Near the surface of the earth, a pendulum could take 4s to complete a cycle if the lenth of the pendulum was about 4m.
13. The period of a pendulum is determined by the length of the pendulum and the acceleration due to gravity. The equation of the period of a pendulum = 2(pi)(sq. root of (length of pendulum/acceleration due to gravity)) Therefore a pendulum on earth with a length of 386.8m.
14. Gravity and the length of the pendulum determine its period. For 4 seconds, you could make a pendulum with a length of about 3.97 meters.
15. The period for a pendulum is decided by 1) how stiff its restoring force is and 2) how big the mass on the end of the pendulum is. The length of the pendulum should be about 4 meters long.
16. The period of a pendulum depends on stiffness and mass, but not on amplitude. Whether amplitude is large or small, its period remains the same. a 3.97 meter pendulum would take 4 seconds to complete a cycle.
17. The period of the pendulum is dependent on the force of gravity and the length of the pendulum. You would use a pendulum that was 3.97 meters long to have a four second period.
18. both the length of the pendulum and gravity determine the period of a pendulum. A pendulum with a period of 4 s would have to be 9.968 m long ( 4 times as tall as the .992 m pendulum which produced a 2 s period).
19. The only thing which determines the period of a pendulum is how stiffly its restoring force pushes it back and forth and on how stubbornly its mass resists that back and forth motion. (it depends on its length and gravity). You could design a pendulum that would take 4 seconds to complete a cycle is have the length of the pendulum be 4cm.
20. A pendulum's period is determined by how stiffly the restoring force pushes back and forth on it and how stubbornly its mass resists that back and forth motion. The stiffer the restoring force the shorter the period. In order for a pendulum to take 4s to complete a cycle the length of the pendulum must be 3.968 meters.
21. A pendulum's period of oscillation depends only on the stiffness of the restoring force and on its mass, not on its amplitude because it is a harmonic oscillator. Because the period of a pendulum does depend on its length and gravity, I just plugged in the numbers into the equation and I figured out that the length of the pendulum would have to be about 3.97m in order for it to have a period of 4s.

Question 2:

Answer:

1. A pendulum clock would not keep accurate time on the moon because the force of gravity is different, therefore the weight of the pendulum would be different, which would alter the restoring force and thereby change its period compared to that when it is on earth. A balance clock also would not keep exactly accurate time, though it would be an improvement over a pendulum clock. A balance clock is subject to the influences of air resistance and thermal expansion, therefore if these were different on the moon then the balance clock would not be entirely accurate. A quartz watch however, would keep accurate time anywhere, including on the moon because the vibrating crystal does not experience friction or air resistence which means it loses energy very slowly, and also the effect of thermal expansion on it is minimal, meaning the crystal's period is just aobut independento f temperature. Therefore the quartz watch would be the one to keep accurate time because all outside influences have very little if any effect on its motion which enables it to serve as a timekeeper.
2. A quartz watch and balance clock. They depend on the oscillation of a balance/spring or a quartz crystal, not the force of gravity to keep accurate time. A pendulum requires the force of gravity to work, and since the period is affected by the force of gravity, the clock would be not accurate on the moon because of less gravity.
3. A pendulum clock would not keep accurate time because the period of the pendulum depends on the acceleration due to gravity. Less gravity means less acceleration which means the period of the pendulum would be less. A simple balance clock would also be affected by a change in gravity and wouldn't keep accurate time. However a balance clock with a balance ring would not be affected because the ring pivots about its own center of gravity so that its weight produces no torque on it. Since its weight doesn't have an effect, the clock would keep accurate time. A quartz watch would also keep accurate time.
4. A quartz watch would keep accurate time on the moon because pendulum and balance clocks use the Earth's gravity, which is not in place on the moon.
5. A balance clock or a quartz watch would still keep accurate time because they don't depend on gravity for their motion. A pendulum clock depends on gravity to pull down the weight that provides the force to keep the pendulum swinging, but since a balance clock relies on a coiled spring and angular motion for its motion, gravity doesn't exert a torque on it, and a quartz watch only depends on the quartz itself vibrating when hit or when it gets an electrical pulse.
6. A quartz watch would keep accurate time because it is the only one that doesn't depend on the force of gravity.
7. A quartz watch would keep accurate time on the moon because it's oscillation is not affected by gravity.
8. A balance clock and a quartz watch would keep accurate time on the moon since gravity plays no role in their operation.
9. The quartz watch would keep time because it relies on constant vibrations that wouldn't change on the moon. However, pendulum and balances both depend heavily on acceleration due to gravity (which affects mass in the balance clock), which would be significantly less on the moon and thus would not keep accurate time relative to earth time.
10. A quartz watch because it acts like a spring with masses at the ends, alternately accelerating.
11. A pendulum clock or balance clock would not because they depend partially on gravity. A quartz watch would work because it is relies on vibrations to keep track of time.
12. The period of a pendulum depends, in part, on gravity. Gravity also affects balance clocks, shifting the equilibrium position of the block part of the clock downward. Of these three clocks, a quartz clock is the only one that is not affected in some way by gravity; therefore, it would keep accurate time if you took it to the moon.
13. all three could keep accurate time on the moon. The pendulum clock, however would have to be recalibrated to the moon's gravity, because gravity affects the period of a pendulum swing. The other two types of clocks are not effected by gravity, so they could keep accurate time without being reclaibrated.
14. A balance clock will work on the moon because gravity does not exert a torque on it.
15. A pendulum clock would not because the gravity would be different so the period of its pendulum would be different than on earth. A balance clock would keep an accurate time because springs do not change because of changes in gravity. A quartz watch would also be fine because it doesn't rely on gravity.
16. Wouldn't they all keep accurate time, due to the absence of air resistance and friction? I'm a bit unsure of this one.
17. The pendulum clock wouldn't work on the moon because it is dependent on gravity. The balance clock could work since the balance ring works around its center of gravity and its weight or gravity exerts no torque on it. The quartz watch would also work in space because it uses vibrations of quarts crystals not gravity.
18. Both the balance cloch and quartz watch would keep accurate time on the moon: the pendulum clock would not since it depends on gravity for its restoring force and the force of gravity on the moon is different than that on the earth. The balance clock, however, has a balance ring which pivots about its own center of gravity so that gravity produces no torque on it. the quartz watch also does not depend on gravity, and additionall is not affected by friction, air resistance and thermal expansion as the other clocks are. its motion relies on crystal vibrations, which lose energy slowly, vibrates for a long times, and the period is independent of its temperature. This also would keep accurate time on the moon.
19. An electronic clock would keep accurate time on the moon becuase it is not affected by a change in gravity.
20. The quartz watch would be most accurate because the other two depend on the acceleration due to gravity and since the gravity of the moon is less than that of earth, the time measurement would be less accurate.
21. I think that the quartz watch would keep most accurate time because it doesn't depend on gravity. The pendulum and the balance ring clocks both would not work on the moon because they rely so much on gravity to keep their oscillation.

Question 3:

Answer:

1. I think I'm okay with the concepts from the reading.
2. The clock thing that uses the balance ring to power itself.
3. The section was really interesting because I've never thought about how clocks worked before. However the descriptions of the different clocks we're kind of wordy, so I think just being able to go over it in class will help a lot.
4. None :)
5. I think I'm good.
6. I don't really understand how the quartz watch works.
7. quartz watches and balance clocks
8. How does a balance ring work?
9. I found this pretty easy.
10. i felt like i understood this section pretty well.
11. I was wondering if you could spend time tomorrow going over the main concepts that will be covered on the test, and maybe do some practice problems. Also, will you be having office hours on Sunday?
12. None; it was helpful to read this section after already having done a lab with pendulums.
13. I think I understand all of the concepts in this chapter.
14. --
15. I would like to go over quartz clocks and how the quartz oscilattor works.
16. Question number two from above, and how a quartz watch works.
17. I found the balance clock difficult to understand
18. I did not understand the discussion of electrical and mechanical "stresses" in the reading. What exactly are stresses?
19. I didnt have any trouble with the reading.
20. The variations of clocks
21. I was actually a little confused at how the clocks worked in general. I think I understand the pendulum one pretty well, but the balance ring and the quartz clocks I did not fully understand how either worked.

Question 4:

Answer:

1. I'm okay with the material as of now.
3. The difference between tricycles and bicycles was sort of hard to grasp.
4. None
5. Nothing- thank you for explaining why bikes need to lean! I really understand it now.
6. nothing
7. none
8. Nothing
9. Still hangin in there.
10. nothing at the moment
11. none
12. None.
13. I feel confident that I understand most concepts from previous classes.
14. --
15. Nothing really.
16. I'm good with past material.
17. i think im good
18. My previous questions have been cleared up, thanks.
19. Im still having trouble with the concept of the elevator, why you would feel heavier when it first starts moving and lighter when it stops.
20. Can we review everything briefly before the test if possible.
21. I think I understood everything so far.