Colegio San PatricioPhysics

WORK AND ENERGYMrs. Nora Guerra

Mrs. Martha Fuentes

Work• Work is done whenever a force (F) is

exerted and whenever there is a displacement (s).

• The amount of work done is proportional to both, the force and displacement.

• (W=F*s)• Work is measured in newton-meters or

Joules.

Formula for work

W

F d

W= workF= forced= distance

Energy

• Ability to do work• No energy: no work• Measured in Joules.

Energy Examples• Energy:• In a raindrop: .0001 Joules• Needed to press a key: .01 Joules

Kinetic enegy• It´s the energy of motion.• An object with motion- whether it´s

vertical or horizontal- has kinetic energy.

Kinetic energy formula• Kinetic energy equals the massof

the moving object times the square of that object´s velocity, multiplied times the constant ½.

• KE= 1/2 mv²

Potential energy

• It´s the energy that can result in the exertion of a force over a distance. It is stored energy.

• Most common= Gravitational PE

Potential energy formula

• Potential energy (joules) = mass (kg)*g(m/s2)*height

(m).