The feather's vertical position
is determined by

We take the feather's starting position to be the origin, and the downward direction to be positive. Then

so the answer is D.
D=s(t) so it would be d=10(.19) d=.19 FOR BITH SNDWERS
A.
if you have seen a newton's cradle this will make sense.
in order for both of them to travel at the same speed, the balls need to have the same mass and the speed to begin with tocontinue to travel at the same speed because mass can affect the impact of the force on the balls by each other, causing each ball to have different speeds.
The concept needed to solve this problem is average power dissipated by a wave on a string. This expression ca be defined as

Here,
= Linear mass density of the string
Angular frequency of the wave on the string
A = Amplitude of the wave
v = Speed of the wave
At the same time each of this terms have its own definition, i.e,
Here T is the Period
For the linear mass density we have that

And the angular frequency can be written as

Replacing this terms and the first equation we have that



PART A ) Replacing our values here we have that


PART B) The new amplitude A' that is half ot the wavelength of the wave is


Replacing at the equation of power we have that


Answer:
due to the inertia of motion, the fan continues to move for some time even after switching it off.