Answer:
1. 175 kgm/s to the west.
2. -21 N (21 N of force in the opposite direction)
Explanation:
1. change in momentum = mass * change in velocity
change in velocity = final velocity - initial velocity
therefore, change in velocity = 8 - 15 = -7 m/s
and the change in momentum = 25 * -7 = -175 kgm/s
In the question, east in defined as the positive direction, therefore the minus sign (-) corresponds to the change in momentum being to the west.
2. The impulse equation is:
Force * change in time = mass * change in velocity
Rearrange this to make Force the subject:
Force = (mass * change in velocity) / (change in time)
Force = (35 * (0 - 9)) / 15 = -21 N
