In the figure: a box moves on a frictionless surface
through a displacement
d = -3 i m. The wind is acting on the box by force F = (2 i – 6 j) N,
a) How much work does F do during the
displacement?
b) If the box has a kinetic energy of 10 J at the
beginning of the displacement, what is the kinetic energy at the end.
Sample Problem 7-3
W = F . d = - 6 J
Kf = Ki + W = 10 – 6 = 4 J
