2017 CAIE AS & A level October November Physics Paper 11 Q N 14 (9702/11/O/N/17) by Sajit C Shakya

2017 Cambridge International AS & A level October November Physics Paper 11 Q. No. 14 (9702/11/O/N/17) by Sajit Chandra Shakya from Nepal
Chapter - FORCES
The diagram shows a motorised vehicle for carrying one person.
The vehicle has two wheels on one axle. The passenger stands on a platform between the
wheels.
The weight of the machine is 600 N. Its centre of mass is 200 mm in front of the axle. The wheel
radius is 400 mm.
When stationary, a passenger of weight 600 N stands with his centre of mass 200 mm behind the
axle to balance the machine.
The motor is now switched on to provide a horizontal force of 90 N at the ground to move the
vehicle forwards.
How far and in which direction must the passenger move his centre of mass to maintain balance?
A 60 mm backwards
B 60 mm forwards
C 140 mm backwards
D 140 mm forwards

[@sparsh684]

Hello Sir!
Shouldn't there be clockwise moment as the wheel rotates in the clockwise direction which causes the motion? Even if the force produce anti clockwise moment how come the wheel rotate in the clockwise direction.