KE, GPE & EPE
This is the type of energy that comes from objects being compressed or stretched.
Elastic Potential Energy.
What is the GPE of an object that is 20 meters off the ground and has a mass of 13 kg?
2,600 Joules
This is know as the energy stored in the bonds of molecules.
Chemical energy
What energy transformation occurs in a fan that you plug into your wall. (Name only 2 forms of energy)
Electrical --> mechanical
The law that states that energy cannot be created or destroyed is known as...
The Law of Conservation of Energy
This is the energy of motion.
Kinetic Energy
What is the kinetic energy of an object that is traveling at 12 m/s and has a mass of 10kg?
720 J
This is the total potential AND kinetic energy of an object.
Mechanical energy
What energy transformation occurs inside of a gas powered grill? (Name only two forms of energy)
Chemical --> thermal
You are bowling with friends and are desperate to win the next round. Would it be better for you to pick a heavier ball or to throw the ball you already have with more force in order to knock down more pins? Why?
Throw it with more force to increase the speed because this has a bigger impact on the kinetic energy of the bowling ball
This is the energy associated with the height of an object.
Gravitational Potential Energy
An object has a mass of 12kg and has 4500 Joules of gravitational potential energy. At what height is this object?
37.5 m
An appliance, like your microwave, is plugged in to use electrical energy, which is also know as the energy of ___________________.
Electrical charges
Connecticut experiences an ice storm. The next day the sun is shining, and the ice begins to melt. What energy transformation is occurring as the sun melts the ice?
Light --> thermal
What is the difference between weight and mass?
Mass is the amount of matter inside of an object and never changes. Weight is an objects mass times the force of gravity.
Think of a bouncing ball. Where in it's fall does it have the most kinetic energy? Why?
At the bottom of the fall because it is moving the fastest.
An object is moving at 17 m/s and has 3600 joules of kinetic energy. What is this object's mass?
24.9 kg
Nuclear energy
Name 3 energy transformations that occur when setting off a firework.
Chemical --> sound
Chemical --> thermal
Chemical --> light
Chemical --> mechanical
A diver has 3600 Joules of potential energy before they jump off the diving board. As they fall through the air, potential energy is converted into kinetic energy. At a point in their dive, they have 1700 Joules of potential energy left. How much kinetic energy do they have in that moment?
1900 Joules
If a skier that has a mass of 54 kg is at the top of the hill that is 150 meters high, how much GPE does that skier have?
81,000 Joules
A ski lift gets stuck halfway up the hill. Your friend, unwilling to wait, decided to jump off the chairlift and free fall to the ground. Jim's weight was 690 Newtons which means his mass was approximately 69 kg. The total distance from the chair to the ground was 20 meters. Assuming the conservation of mass and very little friction. What was the velocity of Jim when he landed on the ground?
20 m/s
This is the AVERAGE kinetic energy of the molecules inside of a substance. This term is often confused with thermal energy.
Temperature
What is the energy transformation that occurs inside of the sun? (There are three types of energy you need to name!)
Nuclear --> thermal & light
You are at the top of a hill that you are about to skateboard down. You and the skateboard have a mass of 73 kg and the hill is 30m high. How much kinetic energy will you have when you are at the very bottom of the hill?
GPE = KE according to the law of conservation of energy so...
GPE = 73*10*30
KE at the bottom = 21,900 J