Conservation
Work & Power
Kinetic Energy
Gravitational Energy
Elastic Energy
100
This law states that energy can be transferred between types, or between objects, but can never be created or destroyed
What is the Law of Conservation of Energy
100
This is the standard unit of measurement for 'Work'
What is a Joule
100
These are the two quantities needed to determine the kinetic energy stored in an object
What is mass and velocity
Ek = 1/2mv2
100
These are the three quantities needed to determine the amount of gravitational energy stored in an object
What are mass, height and strength of gravity ('g')
Eg = mgh
100
These are the quantities needed to determine the amount of elastic energy stored in a spring
What is the strength of the spring (k), and the stretch of the spring (x)
Eel = 1/2kx2
200
When energy is 'lost' due to friction, it is commonly transferred to this 'less useful' form
What is thermal energy (or heat)
200
This is the standard unit of power, also known as a 'joule per second'
What is a Watt
200
This is the kinetic energy of a 5kg ball rolling across a floor at 7 m/s
What is 122.5 Joules
(1/2*5*72) = 122.5
200
This is the gravitational energy of a 10kg mass sitting on a shelf 12 meters above the ground
What is 1200 Joules
(Eg = 10*10*12)
200
This is the elastic energy stored in a spring with a strength of 200 N/m that is stretched to a distance of 50cm
What is 25 J
Eel = 1/2*200*0.52
300
At the lowest point of a pendulum's swing, this type of energy would be at its' maximum
What is kinetic energy
300
These are the two quantities needed to calculate the power of an object
What is 'work' and 'time'
(Power = Work/Time)
300
This is the velocity of a 1200kg car that is storing 20,000 Joules of kinetic energy
What is 5.77 m/s?
300
This is the height of the pillar this rock is sitting on
What is 4 meters?
(3,000 = 75*10*h)
300
This is the law described by the equation
Fspring = -kx
What is Hooke's Law
400
A skateboarder on this ramp has the most total energy at this spot
What is 'all'
The total energy is the same at all positions
400
Fred and Pam are identical twins with the same mass, and need to get to the second floor of their home. Pam walks up the stairs slowly, taking 20 seconds to reach the top. Fred runs up the stairs, reaching the top in 5 seconds. This is the person who does more work to get to the second floor.
What is both Fred and Pam did the same amount of work
(They both applied the same force over the same distance - time does not impact the amount of work done)
400
If the velocity of a falling rock is quadrupled, this is the factor that its' kinetic energy will increase by
What is 16 times as much kinetic energy
400
If a rocket loses 1/4th of its' mass by burning fuel and doubles its' height, this is the factor by which its' gravitational energy has changed
What is half the amount of Eg
400
If the stretch of a spring is reduced by 1/2 as much, this is the factor that the elastic energy stored in the spring changes
What is 1/4th as much elastic energy
500
If the spring shown stores 400 Joules of elastic energy before being released, this is the amount of kinetic energy the ball will have when it is halfway to its’ peak height
What is 200 Joules
(All elastic energy is released into the ball, the ball contains half kinetic and half gravitational when halfway to the peak)
500
The box shown here is moved 5 meters in 4 seconds. This is the power output of the stick-figured gentleman
What is 15 Watts.
(Force x distance) / time
500
If this were a real roller coaster track with friction, the riders would have the most kinetic energy at this point
What is point C
500
When Galileo dropped a 7kg ball from the top of the leaning tower of pisa it hit the ground at 33 m/s. This is the height of the tower.
What is 54.5 meters
(Eg at the top = Ek at the bottom)
mghtop = 1/2mv2bottom
500
If the spring shown is compressed 0.5 meters and pushes the 3kg cart to a final height of 2 meters and is traveling at 12 m/s at the top of the loop, this is the strength of the spring
What is 2,208 J
Egfinal + Ekfinal = Eelinitial