Work (W=Fd) is the measurement of how much displacement (measured in meters) an object experiences as a result from a force (measured in Newtons) acting upon it. The formula for work is used by multiplying the amount of force acting on an object by it's displacement, the distance the object travelled from it's origin. It's important to remember when finding work, that displacement is different than distance. If an object doesn't end up in a different place then from where it began, no work was performed. The unit used to describe work is the Joule. Work is present all around us; a shopping cart being pushed, a person walking upstairs, something being picked up.
Work can be seen in photography when you zoom the lens. When you push a button or manually zoom a lens, the lens extends to get closer to the subject. The displacement is how far the lens moves. Depending on what type of camera you're using, either you or the camera is doing the work.
Questions:
If a photographer is holding a camera at eye level and then lifts the camera above his head to take a photo does he do work? What if the photographer returns the camera to eye level to check his photo?
1) Yes, because the force caused displacement of the camera. 2) No, because though there was force, because the camera returned to its origin there was no displacement.
If it takes 100N of force to zoom a camera lens from 35mm to 88mm, how much work is done?
5.3 Joules
88mm-35mm x 1000 x 100N
If a photographer is holding a camera at eye level and then lifts the camera above his head to take a photo does he do work? What if the photographer returns the camera to eye level to check his photo?
1) Yes, because the force caused displacement of the camera. 2) No, because though there was force, because the camera returned to its origin there was no displacement.
If it takes 100N of force to zoom a camera lens from 35mm to 88mm, how much work is done?
5.3 Joules
88mm-35mm x 1000 x 100N