Chapter 7, Problem 51P

A force $\stackrel{\to }{F}$= (3.00 N) $\hat{i}$ + (7.00 N) $\hat{j}$ + (7.00 N) $\hat{k}$ acts on a2.0 kg mobile object that moves from an initial position of ${\stackrel{\to }{d}}_i$= (3.00 m) $\hat{i}$− (2.00 m) $\hat{j}$ + (5.00 m) $\hat{k}$ to a final position of ${\stackrel{\to }{d}}_f$=−(5.00 m) $\hat{i}$ + (4.00 m) $\hat{j}$ + (7.00 m) $\hat{k}$ in 4.00 s. Find (a) the work done on the object by the force in the 4.00 s interval, (b) the average power due to the force during that interval, and (c) the angle between vectors ${\stackrel{\to }{d}}_i$ and ${\stackrel{\to }{d}}_f$.