An initially stationary crate in is pulled, via a cable, a distance L = 5.70 m
up a frictionless ramp, to a height h of 2.50 m where it stops.
a) How much work Wg is done on the crate by the gravitational force Fg during the lift?
b) How much work WT is done on the crate by the force T from the cable during the lift?
Sample Problem 7-5
Wg = mgd cos (θ+90) = - mg d sin θ                                     = -    mgh
                                   = -368 J
Δ K = Wnet = WT + Wg + WN
0     = WT + Wg + 0 → WT = - Wg
WT = 368 J