Question

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   the man can raise the platform and himself. The total mass of the man plus the platform is 121 kg. What pulling force should the man apply to create an upward acceleration of 1.20 m/s2?

Answer 1

Total mass:-121kg
Acceleration:-1.20
Force:-?
:-Using formula we have F=MA
F=121*1.20=145.2Ans
to check:-F=MA
:-making a subject of formula
A=F/M 145.2/121=1.20
:-The total mass 121kg with acceleration 1.20 will need a force of 145.2

Answer 2

Total mass:-121kg
Acceleration:-1.20
Force:-?
:-Using formula F=MA
whe have:-121*1.20=145.2Ans
to Check:-F=MA making A subject formula we have:-
A=F/M which gives us
145.2/121=1.20
:-The Total mass 121kg with the acceleration 1.20 will need a total force of 145.2

Answer 3

the first thing you always want to do is drawing a free body diagram, you see that there is only 2 vertical forces and no horizontal forces. the +P force & the -W force. Always find your equation symbolically first, using ΣF=MA, 1. P-W=MA, 2. P-MG (since w=mg)=MA, (youre solving for p so add -MG to MA) 3. P=MA+MG or P=M(A+G) 4. plug in numbers P=(121.0 kg)(1.20 m/s^2 + 9.81 m/s^2) 5. P=1332.21 N.