Question

A fixed pulley is driven by a 100 kg mass falling at a rate of 8.0 m in 4.0s. It lifts a load of 75.0 kgf. Calculate the power input to the pulley taking the force of gravity on 1 kg as 10 N.

Answer 1

Load = 75.0 kgf

Mass of falling object = 100 kg

Displacement of effort = 8.0 m

Time taken = 4.0s

Effort = 100 × 10 = 1000 kgf

Power Input

`"P"_"in" = "displacement × effort"/"time"`

= `(8 ×1000)/4`

= 2000 W