A man uses a rope to haul a box of weight600N up an inclined wooden...
A man uses a rope to haul a box of weight600N up an inclined wooden plank of effective length 3.0m and on platform 1.0m high. If in doing so, he exerts a force of 400N on the rope.Calculate:
(I) the frictional force between the case and the plank
(ii) the velocity ratio of the machine
(iii) the mechanical advantage
(iv) the useful work done in joules?