Energy, Work, and Power

Question 1

What is mass?

Answer 1

Amount of material or matter contained in an object (sum of all protons, neutrons, electrons)

Question 2

What is weight?

Answer 2

Gravity’s effect on mass

(Weight = mass x gravity)

This tango that mass does with gravity is why you weigh less on the moon while maintaining the same mass.

Question 3

What are the forms of Energy that this course is concerned with?

Answer 3

Kinetic

Potential

(Energy can be mechanical, heat, or chemical in nature)

Question 4

What is Kinetic Energy?

Answer 4

Energy in motion

KE = 1/2 mv² (mass, velocity)

Question 5

What is Potential Energy?

Answer 5

Energy built up into an object by changing its situation

PE=mgh (mass, gravity, ∆ height)

Question 6

What is the basic unit of Energy?

Answer 6

Joule

Question 7

Formula of a Joule?

Answer 7

1 J = 1 Nm

(amount of Energy expended in the use of 1 N of force over the length of 1 m)

Question 8

Describe work.

Answer 8

It’s what we do!

Energy expenditure where force is applied to generate movement in the direction of force

Question 9

Work. What is its formula? What is it measured in?

Answer 9

Work = Force x Distance

Also measured in Joules (it takes Energy to do Work, son!)

Question 10

What is Power?

Answer 10

The rate of working

OR

The rate of expended Energy

Question 11

What does a Watt measure?

Answer 11

Power.

1 Watt = 1 Joule per second

(1 W = 1 J/s)

Question 12

Formula for Work?

Answer 12

W=FxD

Question 13

Formula for Power?

Answer 13

Kick ass.

Kick more ass than those around you.

Become recognized for kicking so much ass.

Enjoy the Power!

Impose your will onto those that can not match your kick-ass-itude.

Question 14

No, really, what’s the formula for Power?

Answer 14

1 W = 1 J/s

Question 15

What is a Joule, then?

Answer 15

The Energy expended in the application of 1 Newton of force over the distance of 1 meter

(1 Nm)

Question 16

What’s the difference between a DYNE and a JOULE?

Answer 16

A joule is ENERGY EXPENDED to apply 1 N over 1 m

A dyne is the FORCE required to accelerate a mass of 1 g at a rate of 1 cm/s²

(These measures ought not to ever be compared, as they are apples and oranges)

Question 17

How much work is done lifting a 100 kg pt up a distance of 0.020 m to them onto the OR table?

Answer 17

Not enough information. Time elapsed is also needed. If we assume that the action is carried out over the course of exactly 1 second, then 2 J of work has been done.

Question 18

How much work is done pushing on a 100 kg pt on a 75 kg OR table and you can’t get the table to move?

Answer 18

None, you silly billy.