1. A vibrating point on a spring travels 60 mm during three cycles. What is the amplitude of the vibration?
my answer: I got 10 mm but I'm not sure if it is the correct answer.
2. For two connect pendulums to resonate, they must have the same:
a) mass
b) amplitude
c) density
d) length
e) temperature
my answer: d-length
3. What will be the result if a crest with an amplitude of 30 cm overlaps a trough with an amplitude of 5.0 cm?
a) crest with an amplitude of 35 cm
b) trough with an amplitude of 35 cm
c) crest with an amplitude of 25 cm
d) trough with an amplitude of 25 cm
e) crest with an amplitude of 6 cm
my answer: c
1. To find the amplitude of the vibration, we need to know the distance traveled by the vibrating point during one complete cycle. In this case, we are given that the point travels 60 mm during three cycles.
To find the distance traveled in one cycle, divide 60 mm by 3: 60 mm / 3 = 20 mm.
The amplitude of the vibration is half the distance traveled in one cycle. So the amplitude is 20 mm / 2 = 10 mm.
Therefore, your answer of 10 mm is correct.
2. For two connected pendulums to resonate, they must have the same frequency. The frequency of a pendulum is determined by its length. So the correct answer is d) length.
3. When a crest overlaps a trough, the resulting amplitude is obtained by subtracting the amplitude of the trough from the amplitude of the crest.
In this case, the crest has an amplitude of 30 cm, and the trough has an amplitude of 5.0 cm.
Subtracting the amplitude of the trough from the amplitude of the crest, we get 30 cm - 5.0 cm = 25 cm.
Therefore, the correct answer is c) crest with an amplitude of 25 cm.