Terms
IS IT WORK?
Energy transfer
Energy types
Math/RC
100
What is the units for Energy / Work?
Joules
100
Sitting in a chair, taking a quizziz?
No, it is not work
100
An Otter eats a fish and then goes for a swim
Chemical to Kinetic
100
A T.V. produces these two different types of energy?
Light and Sound
100
Deebo Samuel, who has a mass of 90 kg, runs with a velocity of 10 m/s. What is his total Kinetic Energy?
Unknown = K.E.
Equation: K.E. =½ m v2
Givens: m = 90 kg, v = 10 m/s
Solve: K.E. =½ m v2
K.E. = (.5) (90) (10)2
K.E. = 4500J
200
True or False: "kinetic energy is inversely related to height. It is always true that the less height an object has, the more kinetic energy the object has.”
False: It does not depend on height at all
200
Pushing a cart of groceries to your car away from the store?
Yes, it is work
200
A ball rolls up a hill, slowing down as it goes, and then rolls back down, speeding up as it goes.
Kinetic Energy → Gravitational Potential Energy →
Kinetic Energy
200
The fusion of two atoms at the core of the sun is what type of energy?
Nuclear
200
A ball is thrown straight up in the air. At its highest point, the ball has a 980 Joules of Gravitational Potential energy. If the ball’s mass is 10 kg, how high up is the balls highest point.
Unknown = h
Equation: G.P.E. = mgh
Givens: m = 10kg, g = 9.8 m/s2
G.P.E. = 980 J
Solve: G.P.E. = mgh
980 = (10) (9.8) (h)
980 = 98 (h)
h = 10 m
300
What types of energies make up Mechanical?
KE and GPE
300
Trying to stop a moving boulder rolling down the street from hitting a car by pushing it in the opposite direction?
Yes, it is work
300
Plants use energy from the sun in the process of photosynthesis to make glucose, aka sugar.
Nuclear Energy → Light Energy →
Chemical Energy
300
A battery stores this type of energy that eventually gets converted to electrical energy?
Chemical
300
A 2000 kg plane is flying 10000 m in the air. If it is moving with a velocity of 200 m/s, what is the plane’s total Mechanical Energy.
Unknown = M.E.
Equations: M.E. = K.E.+G.P.E. ,G.P.E.=mgh,
K.E. =½ m v2
Givens: m = 2000 kg, h = 10000m, v= 200 m/s, & g = 9.8 m/s2
Solve: M.E. = K.E. + G.P.E.
M.E. =½ m v2 + mgh
M.E. = (.5) (2000) (200)2 + (2000) (9.8) (10000)
M.E.= (40,000,000) + ( 196,000,000)
K.E. = 236,000,000J
400
When work is done on an object it will always be given more _________
Energy
400
Holding a textbook over your head for an entire minute, making sure the textbook doesn’t move?
No, it is not work
400
The Law of Conservation of Energy states
Energy can never be created or destroyed, just transformed from one form into another.
400
Which of the following does not give off air pollution?
Coal, Gas, Nuclear or oil?
Nuclear
400
A bear uses 60 N of force to push a jar of honey 6 meters. How much work did the bear do?
Unknown = W
Equation: W = FD
Givens: F= 60 N, D = 6 m
Solve: W = FD
W = (60) (6)
W = 360 J
500
What is the definition of power?
The rate that work is done
500
Is gravity doing work if I push a tissue box accross my desk?
No, it is not doing work
500
In the picture , from C to D, say whether the type of energy increases decreases or stays the same?
1) Kinetic
2) Gravitational Potential
3) Thermal
4) Total
Mechanical
5) Total
Energy
1)Decreases
2)Stays the Same
3)Increases
4)Decreases
5)Stays the Same
500
In our lab, when was Gravititonal Potential energy always the highest. When the cart was at the _________ point on the track. (Looking for a one word answer
Highest (top)
500
Florence Griffith- Joyner, who weighs 600 newtons runs up a 8 meter flight of stairs in 12 seconds. What is her power rating (note this is a two part problem)
Unknown: Work and Power
Equations: W = FD, P= W/t
Givens: F= 600 N, D = 8 m and t = 12 seconds
Solve: W = FD
W = (600) (8)
W = 4800 J
P = W/t
P = 4800 / 12
P = 400 W