Power, Work, and Energy

Energy

Energy

is the physical quantity that enables a person or an object to do work.

Energy

Without it, it is impossible for a person or object to do work.

Energy

is the ability to do work.

Joules ( J )

What unit is Energy?

4.19 J = 1 calorie

What is the conversion of 1 calorie to Joules?

Energy

can be expressed more specifically by using the term WORK(W)

Work

The Scalar Dot Product between Force and Displacement.

in the direction of the force, energy

If you apply a force on an object and it covers a displacement ___________________ you have supplied ______to, or done WORK on, that object.

Scalar

is a quantity with NO DIRECTION.

cos

In the formula: W = F . d , What is the other meaning of “ . “?

parallel

A dot product is basically a constraint on the formula. In this case it means that F and x must be??

power

The rate of doing work

No, he will not increase the work done if he pulls faster

If a man pulls a crate at a certain velocity, will he increase the work done if he pulls it faster but using the same force?

Student B because they have less time

In a weightlifting class, Student A lifted a 40-kg barbell over his/her head for 15 times in 1 minute and Student B lifted the same barbell over his/her head for 15 times in 30 seconds. Who used up more power? Why?

Kinetic Energy

KE

Potential Energy (U)

PE

Work-Energy Theorem

It basically means that if we impart work to an object it will undergo a CHANGE in speed and thus a change in KINETIC ENERGY.