Answer
Rosie does this work at an average rate of 22 Watts
Work Step by Step
We can find the total amount of work that Rosie does:
$Work = mgh = (220~N)(4.0~m) = 880~J$
We can find the average rate that Rosie does this work:
$Power = \frac{Energy}{Time}= \frac{880~J}{40~s} = 22~W$
Rosie does this work at an average rate of 22 Watts
