A woman pushes a wheelbarrow at a constant velocity on a level road as shown (Fig a). The weight of the wheel is 5 N and the total weight of the rest of the wheelbarrow is 90 N. The centre of gravity of this part is 25 cm from the axle of the wheel and 7'5 cm from the hand of the woman (Fig b). The friction acting on the wheelbarrow is negligible. Find the normal force acting on the wheelbarrow by the ground. A N B GSN C 615 N D 72.5 N