A 600-watt locomotive, moving evenly, covers 200m in 20 seconds. What is its pulling power?

N = 600 W.
t = 20 s.
S = 200 m.
F -?
Power N is the ratio of the work performed A per unit time t.
N = A / t.
Mechanical work with uniform rectilinear movement is determined by the formula: A = F * V. Where F is the force under which the body moves, V is the speed of movement.
Let us find the speed in rectilinear uniform motion knowing that the locomotive has covered the distance S in time t.
V = S / t.
A = F * S / t.
N = (F * S / t) / t = F * S / t ^ 2.
F = N * t ^ 2 / S.
F = 600 W * (20 s) ^ 2/200 m = 1200 N.
Answer: the traction force of the locomotive is F = 1200 N.