Types of Energy Review
Fire releases what type of energy?
Thermal Energy (heat)
Which two variables are used to calculate kinetic energy?
Mass and Velocity
If moving at the same speed, which has more kinetic energy: a mouse or elephant?
Elephant, because it has more mass (size)
If the same size, which has more kinetic energy: a sleeping cat or running dog?
A running dog, because it has more velocity (speed)
What is the kinetic energy equation?
KE = 0.5mv2
(Kinetic Energy = 0.5 x mass x velocity2)
A lightbulb uses what type of energy?
Electrical Energy
What does the "m" stand for in the kinetic energy equation?
Mass (how big an object is)
If moving at the same speed, which has more kinetic energy: a toy car or race car?
Race car, because it has more mass (size)
If the same size, which has more kinetic energy: a soccer ball that is motionless on the ground or a basketball being dribbled?
A basketball being dribbled, because it has more velocity (speed)
If mass = 1 kilogram (kg) and velocity = 2 meters per second (m/s), what is the kinetic energy of that object?
0.5 x 1 x 22 = KE
0.5 x 1 x 4 = KE
0.5 x 4 = KE
2 Joules = KE
Fusion and fission of atoms releases what type of energy?
What does the "v" in the kinetic energy equation stand for?
Velocity (how fast an object is moving)
If moving at the same speed, which has more kinetic energy: a pond turtle or adult cheetah?
Cheetah, because it has more mass (size)
If the same size, which has more kinetic energy: a brick in the wall or a brick falling from a roof?
A brick falling from a roof, because it has more velocity (speed)
If mass = 5 kilogram (kg) and velocity = 4 meters per second (m/s), what is the kinetic energy of that object?
0.5 x 5 x 22 = KE
0.5 x 5 x 4 = KE
0.5 x 20 = KE
10 Joules = KE
What type of energy is stored in the bonds between atoms and molecules?
Chemical Energy
Kinetic energy is measured in "J." What does that stand for?
Joules
If moving at the same speed, which has more kinetic energy: a duck-sized horse or horse-sized duck?
A horse-sized duck, because it has more mass (size)
If the same size, which has more kinetic energy: a slowly dripping ice cube or water gushing from an open fire hydrant?
Water gushing from an open fire hydrant, because it has more velocity (speed)
If KE = 32 J (Joules) and velocity = 4 meters per second (m/s), what is the mass of that object?
0.5 x m x 42 = 32
0.5 x m x 16 = 32
m x 8 = 32
m = 32 ÷ 8
m = 4 kg
Mechanical energy is made up of which two types of energy?
Kinetic Energy and Potential Energy
"J" is measured in "kg m/s." What does that mean?
kg = kilogram (weight)
m/s = meters per second (speed)
If moving at the same speed, which has more kinetic energy: a cup full of water or a cup full of soda of the same size?
Neither, because they both have the same mass (size) and velocity (speed).
If the same size, which has more kinetic energy: a perfectly motionless toy dinosaur or a perfectly motionless pirate eyepatch?
Neither, because they both have the same mass (size) and velocity (speed).
If KE = 27 J (Joules) and mass = 6 kilograms (kg), what is the velocity of that object?
0.5 x 6 x v2 = 32
3 x v2 = 27
v2 = 27 ÷ 3
v2 = 9
v = √9
v = 3 meters per second (m/s)