1) The correct answer is B. 47.09 m
In fact, the work done by the mother is

where F is the force she applied and d is the distance covered by the baby carriage. We are told that the maximum work she can done is
, while the force she applies is F=632 N, therefore by rearranging the previous equation we find the distance travelled by the baby carriage:

2) The correct answer is B. 175 N.
As before, the work done is

where F is the force applied and d is the height at which the mass has been lifted. In this case, W=2100 J and d=12 m, therefore the force used is

3) The correct answer is B. 424 W.
The power is the ratio between the work done and the time taken, so we have:
