Carter pushes a bag full of basketball jerseys across the gym floor. Then he pushes with a constant force of 21 newtons. If he pushes the bag 9 meters in 3 seconds, how much power does he use? (Hint: 1 watt = 1 .)
A.
3 watts
B.
7 watts
C.
27 watts
D.
63 watts
E.
189 watts