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# Power of a Motor: Change in Speed

APPH12-ZARR97

A certain motor is able to pull a $20\ \text{kg}$ block across a frictionless floor, increasing its speed from $10\ \text{m/s}$ to $12\ \text{m/s}$ in $4\ \text{seconds}$.

At what rate is work done by this motor?

A

$10\ \text{W}$

B

$40\ \text{W}$

C

$110\ \text{W}$

D

$440\ \text{W}$