Why do sounds coming from an object moving away from you sound lower in pitch?

Because the object is moving away, the sound waves have a lesser amplitude.

Because the object is moving away, the sound waves are farther apart.

Because the object is moving away, the sound waves have a greater amplitude.

Because the object is moving away, the sound waves are closer together.

B) as the temperature increases, the kinetic energy of the particles increases.|-/

W= fd
where f is an applied force and d is the distance over which it is applied. when a parachuting skydiver is at constant velocity, he is experiencing "terminal velocity", the point at which his acceleration down is canceled out by air resistance. that means that the resisting force of the air is equal to his weight, but in the opposite direction. with this, we can solve for the work done by the force.
w = fd
w = (92.0)(9.81 m/s^2) (325)
w= 2.93 x 10^5 j
the value for work in this case is positive because it is pushing up on the skydiver, who has a downward force of gravity.
therefore the answer is 2.93 x 10^5 j