Page 1 of 1

Work and Energy

PostPosted: January 16th, 2012, 11:08 pm
by Jessica
Work is done when a force causes displacement in the direction of that force; it is the product of the force/displacement and the component of displacement/force in the direction of that force. When done on an object, the object is given energy. Having energy means having the ability to do work.

W = F[sub]x[/sub]Δx or F[sub]y[/sub]Δy

the force and displacement must be parallel

It is a SCALAR quantity

While work can be negative, the negative sign does not refer to direction. Rather, the negative work indicates that energy was lost. Positive work indicates an energy gain.

Re: Work and Energy

PostPosted: September 23rd, 2013, 6:45 pm
by Jessica
A constant force F that moves an object a distance s in the same direction as the force does a work
W = Fs

Re: Work and Energy

PostPosted: September 26th, 2013, 2:02 am
by Jessica
A object of mass m moving with speed v has a kinetic energy defined as the quantity


SI unit: Joules (J)



Work-Energy Theorem

A work done by the net force acting on an object is equal to the change in its kinetic energy.

W = ΔK = K[sub]f[/sub] − K[sub]0[/sub] = ½mv[sub]f[/sub]2 − ½mv[sub]0[/sub]2