A load 80N is raised through a distance of 2cm by a force of 30N which moves through a distance of 8cm when it is applied at one end of a machine. Calculate the efficiency of the machine

To calculate the efficiency of the machine, we need to first determine the work done by the input force and the work done on the load.

The work done is given by the formula:

Work = Force * Distance

For the input force:
Input Work = Input Force * Input Distance

Input Work = 30N * 8cm

Input Work = 240 N.cm

For the load:
Load Work = Load Force * Load Distance

Load Work = 80N * 2cm

Load Work = 160 N.cm

Efficiency is defined as the ratio of useful output work to the total input work.

Efficiency = (Useful Work Output / Total Work Input) * 100%

Efficiency = (Load Work / Input Work) * 100%

Efficiency = (160 N.cm / 240 N.cm) * 100%

Efficiency = 0.67 * 100%

Efficiency = 67%

Therefore, the efficiency of the machine is 67%.