How they are defined by science Work and Power How they are defined by science

Work Work is the product of force and distance The formula is work = force x distance Work is done on an object when a force acts on the object in the direction it moves For example, someone lifting a barbell is doing work on that barbell

Work If there is no movement than no work is being done For work to be done on the object some of the force needs to act in the direction of the object If a weightlifter is just holding the barbell over his/her head than no work is being done since the barbell is not moving

Work = force x distance The unit for work is Joule (J) For example if the weightlifter lifted the barbell. Calculate the work done if the barbell weighs 1600 Newtons and he lifts the barbell 2 m. It would be: W = 1600N x 2m = 3200 J

Power Power is the rate of doing work Doing work at a faster rate requires more power To increase work you can increase the amount of work done in a given time or do a given amount of work in less time

Power Power = work/time = distance x force time The unit for power is the watt which is equal to one joule per second So it takes 40 joules per second to light a 40 watt lightbulb

Horsepower A common unit for power One horsepower is equal to 746 watts Horsepower was first defined by Scottish scientist James Watt He used horses to compare the power of his steam engines He did not want to exaggerate the power so he used the strength of a very strong horse