A gardener pushes a 17 kg lawnmower whose handle is tilted up 37∘

Question

above horizontal. The lawnmower's coefficient of rolling friction is 0.18. How much power does the gardener have to supply to push the lawnmower at a constant speed of 1.5 m/s ? Assume his push is parallel to the handle.

I calculated it to be 56.3810 W, by calculating the Force of Friction and then multiplying that by the speed however Mastering Physics is not accepting it. Am I doing something wrong?

Answer 1

haven't done the calculation yet, but your significant figures are incorrect

everything in the question is 2 sig fig
... your answer has six

just because your calculator shows it, doesn't mean it belongs

Answer 2

I typed in 56 as well and it marked it as incorrect.