Chapter 5 Section 1: What is Energy?

Energy

Energy is the ability to do work

Work is done when a force makes an object move or change its direction.

Example When you kick a soccer ball, you are doing work on the ball and then the ball does work on the goal.

When one object does work on another, energy is transferred.

Energy is expressed in the units Joules (J)

Kinetic Energy

Kinetic energy is the energy of motion

Kinetic energy is the energy of motion

All moving objects have kinetic energy.

Kinetic energy depends on mass and speed Kinetic energy= mv2/2 M=mass V2=velocity2

To increase kinetic energy, increase the mass(m) or speed(v) of the object.

Potential Energy

Potential energy is the energy an object has because of its position

There is more potential energy in a car on top of a hill than a car on a flat street.

Gravitational potential energy is a transfer of energy to an object by lifting it in the air.

Holding a ball over your head vs it resting on the ground. Example Holding a ball over your head vs it resting on the ground.

To calculate gravitational potential energy: weight x height

Weight is the amount of force needed to lift an object and height is a distance

Mechanical Energy

Mechanical Energy is the total energy of motion and position of an object

potential energy+kinetic energy Mechanical energy= potential energy+kinetic energy

Other forms of energy Thermal Energy Chemical Energy Electrical Energy Sound Energy Light Energy Nuclear Energy