Efficiency = (useful output) / (input)
Efficiency = (35 J) / (125 J) = 0.28 = 28%
According to the position vs time graph, the <em>average</em> <em>velocity</em> of the motorcycle is the change in position divided by the change in time. Also, note that the slope is linear and positive throughout the 5 hours, it doesn't change direction.
Therefore, we have
Avg velocity = change in direction/change in time
Avg velocity = (150km - 30km)/(5h - 0h)
Avg velocity = 24km/hr south.
<span>When two objects collide their momentum after the collision is explained by</span> the conservation of momentum
