Question

A man of mass 80.0 kg stands on a platform of mass 40.0 kg. He pulls on a rope that is fastened to the platform and runs over a pulley on the ceiling. With what force does he have to pull in order to give himself and the platform and upward acceleration of 1.0 m/s²?

Answer 1

Answer:F=648 N

Step-by-step explanation:

Given

mass of man
`m_1=80 kg`

mass of Platform
`m_2=40 kg`

acceleration of system
`a=1 m/s^2`

Let F be the force with which man pulls the rope which will also create a tension of F in rope

From Diagram

`2F-(m_1+m_2)g=(m_1+m_2)a`

`2F=(m_1+m_2)(g+a)`

`F=((m_1+m_2)(g+a))/(2)`

`F=((80+40)(9.8+1))/(2)`

`F=(1296)/(2)`

`F=648 N`