1) The correct answer is B. 47.09 m
In fact, the work done by the mother is
[tex] W=Fd [/tex]
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 [tex] W=2920 J [/tex], while the force she applies is F=632 N, therefore by rearranging the previous equation we find the distance travelled by the baby carriage:
[tex] d=\frac{W}{F}=\frac{2920 J}{62 N}=47.09 m [/tex]
2) The correct answer is B. 175 N.
As before, the work done is
[tex] W=Fd [/tex]
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
[tex] F=\frac{W}{d}=\frac{2100 J}{12 m}=175 N [/tex]
3) The correct answer is B. 424 W.
The power is the ratio between the work done and the time taken, so we have:
[tex] P=\frac{W}{t}=\frac{2120 J}{5 s}=424 W [/tex]
