In the figure: Two men slide an initially stationary
safe of mass m=225 kg on a frictionless floor. F1 =12.0 N and F2 = 10.0 N
a)What is the net work done on the safe by F1 and F2
during the displacement d.
a)during the displacement d, what is the work done by the weight of the safe and the normal force?
b)What is the final speed of the safe if d= 8.50 m?
Sample Problem 7-2
W1 = F1 cos
(30o) d
W2 = F2 cos
(40o) d
Wg = 0
WN = 0
½ mv2 = Wnet =
W1+ W2+ Wg+ WN