A child pushes a merry-go-round by applying a force tangential to the platform (Figure P...

A child pushes a merry-go-round by applying a force tangential to the platform (Figure P8.11). To maintain a constant rotational speed of 40 rpm, the child must exert a constant force of 90 N to overcome the slowing effects of friction in the bearings and platform. Calculate the power exerted by the child in horsepower to operate the merry-go-round. The diameter of the platform is 8 ft.