Work and Energy
What is an example when an object has gravitational potential energy
book on shelf, man hanging off a cliff .... anything off the ground
What is the SI unit for power?
Watts or Joules/Second
What is Kinetic Energy?
the Energy of Motion
What is potential energy.
Energy when an object is still; Energy related to position.
What is the formula for work?
W=Force X Distance
What types of energy are involved in eating a cookie?
Chemical, mechanical....
How many Watts equal 1 unit of Horsepower?
746 Watts
What is the formula for KE?
KE= .5(mass)(v2)
Define gravitational potential energy?
When is work done and not done when holding a barbell over your head?
When the barbell is being lifted but not at the top when it is still.
What types of energy are involved in a lit flashlight?
Chemical, Electrical, Mechanical
What is the formula for power
P=W/T
What is the Kinetic Energy of a 10 Kg ball moving at 5m/s ?
125 J
What type of energy is involved in a rubber band that's pulled back?
Elastic Potential
What is the unit for Work and Energy?
Joule
A hydroelectric dam involves what kinds of energy?
Kinetic, mechanical, electric, Gravitational Potential
Who does more work? Spencer walking up the 20 m high staircase carrying his backpack in 10 seconds, or John running up the same staircase carrying a backpack in 3 seconds?
Same work (John has more Power)
What is the Kinetic Energy of a 15 Kg bowling ball sitting on the shelf ?
O J
What is the potental energy of a 3 Kg book on Earth on the ground?
0 J
1) How much work is done if you push a 200N crate for 4 meters?
800 Joules or N*m
What is the law of conservation of energy.
Energy is never created, lost, or destroyed, it just changes form.
What is the power of a runner runs up a flight of stairs using 200J of work in 10 seconds ?
Power: P=W/T= 20 Watts
What is is the Kinetic Energy of a 300 Kg dog running at 3m/s ?
1350 J
An object has a mass of 250 kg. It is 20 m above the ground. What is the PE?
49000 J