Question

A window washer on a hanging platform cleans the outside of windows on a skyscraper. The washer hoists the platform up the side of the building by pulling down on a rope that runs up over a pulley and then runs back down and connects to the top of the platform. The combined mass of the washer and the platform is 100kg, and the washer pulls on the rope with a force of 800N. What is the acceleration of the platform?

Answer 1

Answer:

Acceleration of the platform = - 1.8 m/s²

Explanation:

The net force acting on a body accelerates the body in the same direction as that in which the resultant is applied.

Writing the force balance for the setup,

ma = 800 - mg

100a = 800 - 100×9.8

100a = - 180

100a = - 180

a = - 1.8 m/s²

This means the body falls downwards.