What is mass?
Amount of material or matter contained in an object (sum of all protons, neutrons, electrons)
What is weight?
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.
What are the forms of Energy that this course is concerned with?
(Energy can be mechanical, heat, or chemical in nature)
What is Kinetic Energy?
Energy in motion
KE = 1/2 mv2 (mass, velocity)
What is Potential Energy?
Energy built up into an object by changing its situation
PE=mgh (mass, gravity, ∆ height)
What is the basic unit of Energy?
Formula of a Joule?
1 J = 1 Nm
(amount of Energy expended in the use of 1 N of force over the length of 1 m)
It's what we do!
Energy expenditure where force is applied to generate movement in the direction of force
Work. What is its formula? What is it measured in?
Work = Force x Distance
Also measured in Joules (it takes Energy to do Work, son!)
What is Power?
The rate of working
The rate of expended Energy
What does a Watt measure?
1 Watt = 1 Joule per second
(1 W = 1 J/s)
Formula for Work?
Formula for Power?
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.
No, really, what's the formula for Power?
1 W = 1 J/s
What is a Joule, then?
The Energy expended in the application of 1 Newton of force over the distance of 1 meter
What's the difference between a DYNE and a JOULE?
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)
How much work is done lifting a 100 kg pt up a distance of 0.020 m to them onto the OR table?
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.
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?
None, you silly billy.