Physics test 1 work

Energy

Required to do work, comes in many forms

What are the different forms of energy?

Potential, gravitational potential energy, kinetic, thermal, electric, light, chemical, nuclear

Law of Conservation of Energy

energy cannot be created nor destroyed, only changed from one form to another

What happens when work is absent?

Energy stays the same

Work

produces a change in energy

What does work on an object do?

Puts energy in

What does work by an object do?

Takes energy out

Work equation

W= Fxd

Joule

Mks unit, named for James P Joule,1 joule of work is the product of 1 newton of force moving throuh 1 meter of distance, 1 joule is small

Pound

foot: English unit, 1 pound x foot of work is product of 1 pound of force moving through 1 foot of distance

Gravitational Potential Energy

energy due to position within a gravitational field

What is the equation for PE?

PE= mgh

Kinetic Energy

energy of mass in motion, scaler

What is the equation for KE?

½ mv²

What is energy conservation?

When work is not done, energy is constant. An object can trade one form for another but the total remains the same. I.e., coast downhill on a bike, height decreases but speed increases, trade PE for KE

How do you change energy?

Work is required. Work is put into the system to increase its energy or work is taken out of the system to decrease energy

Energy is required to do ______

work

Is liftin a weight work?

yes

is holding a weight in the air work?

No

Is carrying your backpack up the stairs work? ____ Do you work carrying it down the hall?_____

Yes, no

Is work required to put a satellite into orbit?____ Is work required to keep it there?____

yes, no