Man pulling a pulley?

A man is standing on a platform that is connected to a pulley arrangement, as the drawing shows. By pulling upward on the rope with a force, P, the man can raise the platform and himself. The total mass of the man plus the platform is 102 kg. What pulling force should the man apply to create an upward acceleration... show more A man is standing on a platform that is connected to a pulley arrangement, as the drawing shows. By pulling upward on the rope with a force, P, the man can raise the platform and himself. The total mass of the man plus the platform is 102 kg. What pulling force should the man apply to create an upward acceleration of 1.20 m/s2?

Can anyone help me with this?

I did F=MA

F = 102Kg(Total mass)*1.20m/s2(Acceleration)
= 122.4 N

Which was incorrect, except for the units.

Help please, 10 points.
6 answers 6