A hot air balloon is acted on by two forces. One force is its weight, equal to 2448 newtons. The second force is a buoyant force acting straight up,
equal to 2448 newtons. What change in the motion of the balloon will
result from the action of these two forces?
no change
rising
falling

Answer(b) 60 miles per hour;

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

D. the index of refraction of the second medium is lower.