A string fixed at both ends is vibrating in one of its harmonics. If we now increase only the frequency at which the string is vibrating, which of the following characteristics do we also increase? There could be more than one answer. A) The period of the traveling waves on the string
B) The wavelength of the traveling waves on the string
C) The speed of the traveling waves on the string.
D) The amplitude of the traveling waves on the string.
E) None of the above

Options C

The speed of the travelling waves on the string.

Explanation:

When a string fixed at both ends is made to vibrate faster, this is the same as increasing the frequency of the wave traveling through the string.

from the wave equation,

v = velocity of the wave

f = frequency of the wave

λ = wavelength

We can see that the speed (velocity) of the waves travelling in the string increase once the frequency increases. this is because there is a direct proportionality between the two wave parameters. This makes option C correct.

The others are wrong for the following reasons:

Option A: The period decreases with increasing frequency

Option B: The wavelength decreases with increasing frequency

Option D: The amplitude is not affected by the frequency

when two balls of the different masses are dropped from equal height, they reach the ground at the same time .this is because they experience the same acceleration.

the acceleration is independent of mass.

thus when they are dropped they will always maintain the same velocity and travel the same distance (neglect air resistance of course) at the same time.