Answer:

Explanation:
We are given that
Initial velocity=u=18ft/s
Final velocity,v=38ft/s
Time=t=3 s
We have to find the average acceleration over that 3 s period.
We know that
Average acceleration,a=
Using the formula
Average acceleration,a=
Average acceleration,a=
Average acceleration,a=
Hence, the average acceleration=
The correct order is (in decreasing order of gravity strength)
Jupiter - Neptune - Venus - Mars
In fact, Wayne's weight on each planet is given by

where m is Wayne's mass, which is a constant value, and g is the gravity strength at the surface of the planet. Therefore, the Wayne's weight W on each planet is directly proportional to the gravity strength of that planet: so the planet with the strongest gravity is the one where Wayne's weight is the greatest (Jupiter, 333 pounds), followed by Neptune (159), Venus (128) and Mars (53).
T= 24.5 feet per second. That is the velocity it reaches at the end of its fall
A sound wave. Because in a vacuum there is no medium in a vacuum. And the only wave that requires a medium to travel through is a sound wave.