A box moving to the right experiences four forces, as shown. Key
F = 10 N
V
F = Normal Force
F, Friction Force
F = Force due to Gravity
FA = Applied Force
F, 15 N
F = 15 N
F. = 10 N
If these forces are applied for a given time interval, t, which statement describes what the box will do during
that time?
A. The box will slow down during the time interval
B. The box will maintain a constant velocity.
C. The box will speed up during the time interval.
D. The box will change direction but not speed.

Letter c i’d say

This is what a calorimeter is used for simpler ex, to measure calories in food.

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