Answer:
A, 72 kg•m/s
Explanation:
p=mv
p=18x4
p=72
v = 400m/58s = 6.9m/s
v = 400m/60s = 6.7m/s
6.9m/s - 6.7m/s = .2m/s difference
60sec - 58 sec = 2 sec
v =Δx/t
Δx = vt
Δx = (.2m/s)(2sec)
Δx = .4m
therefore, the answer is .4m