### Present Remotely

Send the link below via email or IM

• Invited audience members will follow you as you navigate and present
• People invited to a presentation do not need a Prezi account
• This link expires 10 minutes after you close the presentation

Do you really want to delete this prezi?

Neither you, nor the coeditors you shared it with will be able to recover it again.

# Energy

is a measure of the ability to do work
by

## Linda Bowman

on 21 February 2014

Report abuse

#### Transcript of Energy

Whenever you do work on a object,
for example lifting a concrete block,
drawing back on a bow, or
pushing a wheelbarrow,
the work you have done is transformed
into some other form of energy.
Potential Energy
Kinetic Energy
Conservation of Energy
Energy
The energy the object now possess can, in turn, do work on sommething else.
energy is a measure of the ability to do work. The two are directly related and both are expressed using the same units ...joules.
One of the two main cateorgies of mechanical energy; Potenital Enery, PE, is stored energy.
a concreteblock resting precariously on a steel beam 30 floors above a side walk.
a fully drawn bow can launch an arrow with a relatively high speed
One of the two main categories of mechanical energy; Kinetic energy or KE is energy due to motion
a heavily loaded wheelbarrow rolling down a hill
arrow traveling toward a target
2 types of potential energy
a)Elastic Potential Energy- energy stored in an object which has been stretched, compressed,
or flexed

Example- springs, rubber band, crossbow, pole
vault, diving board, bungee cord
More on kinetic energy
Any object in motion has kinetic energy,
the more kinetic energy it has,
the more diffcult it becomes to stop the object.

If we consider stopping a moving automobile,
we might easily speculate that kinetic energy will depend upon (two things)...
the mass of the object, and
how fast it is moving
KE= 1/2mv2

Notice that Kinetic energy is more dependent upon speed than on mass.

For instance, doubling the mass of an object, doubles the KE.

However, if you double the speed...
...since the speed is squared in the equation...
Energy cannot be created or destroyed;
it may be transformed from one form to another, but the total amount of energy never changes.

While forces such as friction and air resistance, or forma of energy like heat, light, and sound, might appear to take energy from the system, in fact, the energy has simply changed form.
b)Gravitational Potential Energy- energy stored in an object because of its vertical location

Obviuosly, you do more work lifting a massive
object than you will lifting a lighter
object. And, the higher the object is
located above something the more energy the
object will possess. Likewise, the lower an
object is initially situated below some
height, the more work you do to raise it up.

Thus, gravitational PE must somehow depend on an object's weight, and it's height.

PE= mgh
Full transcript