# Solved: Simple Force Problem: 80KG Man Exerts 20N

• Slayergnome
In summary, the problem involves an 80 kg man being lowered using a massless cable over two pulleys. With a downward acceleration of 0.2 m/s^2, the force exerted by the man on the cable is 20 N if gravity is ignored. However, considering gravity's force of 9.8 N, the calculation becomes -980 + 3t = 100 kg * 0.2 m/s^2, where t represents the force exerted by the man. Taking into account the diagram provided, the solution is t = 320 N.

## Homework Statement

An 80 KG man is standing on the platform of mass 20 KG is lowering him self down using a massless cable passing over two pullies. If his downward acceleration is .2 M/S^2, find force exerted by the man on the cable.

## Homework Equations

I thought it was a simple
F=M*A

## The Attempt at a Solution

F= (100 Kg) * (.2 m/s^2)
F= 20 N

That is correct, provided gravity is ignored.

If you do not intend to ignore gravity, remember that gravity exerts a force of 9.8 N (g) at the surface of the Earth.

I am and idot, thanks for the gravity tip also ther is a diagram I did not provide taht is very important, just out of curiosity do you put pictures on here using HTML type.

Calculation is
-980 + 3t=100kg*.2
3t=-20+980
t=320 N
The reason it is 3t is because the diagram shows the rope connecting the celling and the platform/man 3 times with the two pullys)

Slayergnome said:
I am and idot, thanks for the gravity tip also ther is a diagram I did not provide taht is very important, just out of curiosity do you put pictures on here using HTML type.

Calculation is
-980 + 3t=100kg*.2
3t=-20+980
t=320 N
The reason it is 3t is because the diagram shows the rope connecting the celling and the platform/man 3 times with the two pullys)

I believe HTML is disabled, although you could upload the image and use IMG tags, I believe.