Conceptual AP physics problem help

Discus: SAT/ACT Tests and Test Preparation: October 2003 Archive: Conceptual AP physics problem help
 By Delirious (Delirious) on Wednesday, October 01, 2003 - 05:20 pm: Edit

A man is sitting in a bosun's chair that dangles from a massless rope, which runs over a massless, frictionless pulley and back down to the man's hand. The combined mass of the man and chair is 95.0kg. With what force magnitude must the man pull on the rope if he is to rise (a) with a constant velocity and (b) with an upward acceleration of 1.30m/s^2?

 By Bigman82085 (Bigman82085) on Wednesday, October 01, 2003 - 10:31 pm: Edit

a) the answer is the weight of the man plus the chair, or appx. 931 newtons.

b) the total force is 95*1.3 or 124 N upwards (keep in mind sig figs). you have the force of weight (931N) pulling downwards. so, if x is the magnitude of the pulling force, x-931=124. therefore, x=1055N.

 By Delirious (Delirious) on Thursday, October 02, 2003 - 10:40 am: Edit

nope...it's not right. You have to do 2T but I don't really understand it because I thought it would still only be one tension force.