Show:
Work
Power
Kinetic Energy
Potential Energy
Grab Bag
100
What is the SI unit for Work?
What is a Joule
100
What is the SI unit for power?
Watt is the Watt. See Watt I did there?
100
Under what conditions does an object possess kinetic energy?
What is...when the object is in motion.
100
What scenario would cause a change in an object's gravitational potential energy.
What is a change in elevation.
100
Work divided by Displacement
What is Force.
200
What is the definition of energy?
What is the ability to do work.
200
What unit of power did James Watt establish? and why?
Watt is the horsepower. As a marketing ploy to sell his steam engines.
200
How are heat and kinetic energy related?
What is...Heat is the kinetic energy of the atoms and molecules within an object.
200
What is the gravitational potential energy of a 200 kg object that is sitting on top of a cliff that is 50 meters high?
What is 98,100 Joules
200
Work output divided by Work input
What is efficiency.
300
When holding a barbell above one's head, is there work being done on the barbell? Explain
What is No - there is no displacement of the barbell, therefore, it has no work being done on it.
300
In a time of 13 seconds, a 70 kg student runs up three flights of stairs whose combined height is 8 meters. Compute the students power in horsepower.
What is .57 horsepower.
300
A 3 kg block initially traveling at 9 m/s crosses over a 2 m wide frictional area with a coefficient of friction of .17. What is the block's final speed?
What is 8.62 m/s?
300
What factors determine the elastic potential energy stored in a spring?
What are the stiffness of the spring (k value), and the amount of stretch (or compression) of the spring?
300
In all real mechanical systems energy is said to be "lost" to friction. Where does that energy "go"?
What is heat? Increase in the molecular motion (kinetic energy) of the parts in the system.
400
How much work is done by a 75 kg man who runs up a flight of stairs that is 12 meters high, and how does it compare to a man who walks up the stairs?
What is 8829 Joules, and the amount of work is the same.
400
How many minutes does it take a 30 Watt motor to lift a 2,300 N weight a distance of 5.5 meters? Assume 100% efficiency for the motor.
What is 7 min?
400
A frictionless roller coaster car is on top of a hill that is 30 m high with an initial speed of 25 m/s. What is the maximum height that any of the remaining hills can be?
What is 61.9 m?
400
Look at the drawing that Mr. Schmidt will create on the board for you.
What is...No. The cart would only make it up 9.3 m
400
Look at the awesome picture Mr. Schmidt will draw on the board for you....stop laughing!!!
What is 4.26 m/s
500
How much work would you have to exert to drag a 25 lb. table 12 meters across a brick floor with a coefficient of kinetic friction between the table and the floor is u = .6? Express your answer in Joules.
What is 801 Joules?
500
How much does it cost to run an 1,800 Watt hair drier for 30 minutes, if you pay $.1/KWh from your local "power" company?
What is 9 cents?
500
When a car with an initial speed hits a wall and comes to a complete stop, is it safe to say that the energy transferred to the wall is still kinetic energy, and what form of energy is it. Please explain.
What is Heat and yes it is kinetic energy because heat is the movement of microscopic particles that are moving faster since they have more energy.
500
A pogo stick spring is compressed 25 cm and gets released. If the mass of the pogo stick on the person jumping on it is 85 kg, and the force constant of the spring is 4500 N/m, how high with the person go?
What is .16 meters?
500
Find Vf from the picture that Mr. Schmidt will provide.
What is 5.77 m