Answer:
(C) Only if it starts moving
Explanation:
We know that work done is given by

So there are two case in which work done is zero
First case is that when force and displacement are perpendicular to each other
And other case is that when there is no displacement
So for work to be done there must have displacement, if there is no displacement then there is no work done
So option (c) will be the correct option
Answer:
u= 187.61 ft/s
Explanation:
Given that
g= - 32 ft/s²
The maximum height ,h= 550 ft
Lets take the initial velocity = u ft/s
We know that
v²=u² + 2 g s
v=final speed ,u=initial speed ,s=height
When the object reach at the maximum height then the final speed of the object will become zero.
That is why
u²= 2 x 32 x 550
u²= 35200
u= 187.61 ft/s
That is why the initial speed will be 187.61 ft/s
The energy of the wave is D) 16.0 units squared
Explanation:
The energy of a wave is directly proportional to the square of the amplitude of the wave.
Mathematically, this can be written as

where
E is the energy of the wave
A is its amplitude
For the wave in this problem, the amplitude is
A = 4 units
Therefore, assuming that the constant of proportionality is 1, the energy of this wave is
units squared
Learn more about waves:
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brainly.com/question/9077368
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Potential Energy (energy that is stored as a result of position or shape)