# Efficiencey of a jack

• tuffshorty
N. In summary, the efficiency of the jack is 7% because the work output is 50 N x 0.07 m = 3.5 Nm and the total work input is 50 N x 0.001 m = 0.05 Nm.

#### tuffshorty

The end of the lever of a tire jack travels 7 m for every centimeter that it lifts the car. If the car has a mass of 1000 kg and a force of 50 N is needed to lift the car, what is the efficiency of the jack

Efficiency = useful work output/total work input
w = F x d, where w is work, F is force, and d is distance. (If given mass instead of force, force is found by multiplying mass (in kg) by 9.8 m/sec2 (acceleration of gravity on earth)

the useful work input would be .05 correct? because you would take the 50 N the force times the distance .001 m but i don't know how to find the work output as it doesn't tell a force.. am i missing something?

You are almost there !
Efficiency = work out / work in
work = force * distance

So Efficiency = (weight_car * distance car) / (force_jack * distance jack)

but i don't know what the force on the jack is...

It says 50N

## What is the definition of efficiency of a jack?

The efficiency of a jack refers to the percentage of energy input that is converted into useful work output by the jack.

## How is the efficiency of a jack calculated?

The efficiency of a jack is calculated by dividing the output work by the input work and multiplying by 100%.

## What factors affect the efficiency of a jack?

The efficiency of a jack can be affected by factors such as friction, mechanical wear and tear, and the quality of the materials used in its construction.

## How can the efficiency of a jack be improved?

The efficiency of a jack can be improved by reducing friction through proper lubrication, using high-quality materials, and maintaining the jack regularly to prevent wear and tear.

## Why is the efficiency of a jack important?

The efficiency of a jack is important because it directly affects the amount of work that can be done with a given amount of energy input. A higher efficiency means less energy is wasted, resulting in cost savings and better performance.