The wave diagramed in blue.
Answer:
Explanation:
We could use the following suvat equation:
where
s is the vertical displacement of the coin
v is its final velocity, when it hits the water
t is the time
g is the acceleration of gravity
Taking upward as positive direction, in this problem we have:
s = -1.2 m
And the coin reaches the water when
t = 1.3 s
Substituting these data, we can find v:
where the negative sign means the direction is downward.
I would say A not 100℅ thou
Weight = (mass) x (acceleration of gravity)
Acceleration of gravity = 9.81 m/s² on Earth, 1.62 m/s² on the Moon.
The feather's weight is . . .
On Earth: (0.0001 kg) x (9.81 m/s²) = <em>0.000981 Newton </em>
On the Moon: (0.0001 kg) x (1.62 m/s²) = <em>0.000162 N</em>
The presence or absence of atmosphere makes no difference. In fact, the numbers would be the same if the feather were sealed in a jar, or spinning wildly in a tornado, or hanging by a thread, or floating in a bowl of water or chicken soup. Weight is just the force of gravity between the feather and the Earth. It's not affected by what's around the feather, or what's happening to it.
The used work of energy output is 496*2.1=1041.6 J. And the actual work of energy output is 1127*0.85=957.95 J. The percentage efficiency is 957.95/1041.6*100%=91.97 %.
