Show:
Energy
Power
Work
Friction
100

What is energy?

Energy is the force that allows objects to move

100

What is power measured in?

Watts

100

What is work?

A force acting upon an object over a certain distance with acceleration
100

In a perfect world, why does thermal energy not exist?

Because friction does not exist
200

What is the equation for potential energy?

U=mgh

200

What are the three equations for power?

p=v^2/R

p=w/t

p=E/t

200

Work is done with constant velocity. True or False?

False

200

What did the skater in the Phet Lab show us?

When friction exists, eventually all of the skater's energy will be thermal
300

What is the difference between kinetic and potential energy?

U = energy stored in an object, T= is energy based on movement
300

If Sally has a work of 40J for 8 seconds, how much power did she generate?

5 Watts

300

Why does the work-energy theorem work?

Net work done by the forces on an object = the change in its kinetic energy
300

If there are 5 N of friction opposing the movement of Sally moving 1072 N, how many would she exert without friction?

1077N

400

What is the statement of conservation of energy?

Energy can never be created or destroyed
400

If John does 50J of work in 5 seconds and Bob does 40J of work in 3.5 seconds. Who has more power?

Bob

400

Brad is pushing a heavy freezer with a mass of 80kg in a 100 meter race. He is trying to pass the competition and has an acceleration of 25m/s^2. How much work (Joules) is done by Brad?

200,000 Joules

500

Bobby with a mass of 1000kg is in a frictionless skateboarding simulation. She starts off at the top of a 500m ramp and has a constant velocity of 150m/s. Find kinetic, potential, and total energy. 

T=22,500,000

U=4,900,000

Total=27,400,000

500

Sally is moving to her new apartment. Sally wants to carry a box with a mass of 38kg a distance of 200 meters to get up the stairs. She is a fast walker and has an acceleration of 20 m/s^2. It takes Sally a total of 45 seconds to get up the stairs. How much power (Watts) did she generate?

3377. 78 Watts

500

What is the ENTIRE work energy theorem?

W = ΔT = ½ mv22 - ½ mv12 ⇒ ½ m(v22- v21)