Vocabulary
The ability to do work or cause change.
Energy
How do you calculate velocity (speed)?
What is the velocity of a car moving 200m is 10s?
Velocity + distance/time.
200m/10s = 20m/s
What location on a roller coaster has the most potential energy.
The top of the first (largest) hill has the most potential energy.
A solar panel converts radiant energy into what form of energy.
Electrical
What is mechanical energy? How do you find it?
1.What if a falling apple has 2J of potential energy and 4J of kinetic energy, what is it's mechanical energy?
2. If a mechanical energy of a falling apple is 6J and the kinetic energy is 3J, what is the potential energy?
Mechanical energy is energy due to the position or movement of an object. The formula for mechanical energy is mechanical energy = kinetic energy + potential energy.
1. 2J (potential) + 4J (kinetic) = 6J (mechanical)
2. 6J (mechanical) = 3J (kinetic) + ?J (potential)
6-3=3
What are two types of potential energy? Give an example of each.
Two types of potential energy are gravitational potential energy and elastic potential energy. Gravitational potential energy is a rock at the top of a hill. Elastic potential energy is stretched rubber band.
How do you calculate work? What 2 things have to happen for work to occur?
1. How much work is done if a person lifts a 2N bag 3 meters off the ground?
2. How much work if done if a person carries the 2N bag 10m to his car?
3. How much work is done if a person tries to push his 200N car out of a ditch but the car does not move?
Work is calculated force x distance. For work to occur, the object has to move and it has to move in the direction of the force.
1. 6J
2. 0J - because the distance is not in the direction of the force
3. 0J because the car does not move.
On a rollercoaster, as potential energy decreases, kinetic energy____________.
Increases
A light bulb converts electrical energy into what two energies?
Radiant and thermal. (Light and heat).
When you eat an apple, your body transforms _____ energy into ______ energy
Chemical into mechanical.
What is the difference between kinetic and potential energy? Give and example of each.
Kinetic energy is the energy an object posses by virtue of being in motion. Potential energy is the energy an object posses as a result of its position or shape. Potential energy is a roller coaster at the top of a hill. Kinetic energy is the roller coaster at the bottem.
What is power? How do you calculate power?
Power is the rate (speed) at which work is done. Power is calculated as work(force x distance)/time.
What are two variables that affect gravitational potential energy.
Mass and height
What kind of energy is stored in food?
Chemical Energy
When we burn wood in a fire, we are converting this form of energy and turning it into heat energy.
Chemical energy
This law states that energy is never created or destroyed, it is only changed from one form to another.
The Law of Conservation of Energy
How do you calculate kinetic energy? How much kinetic energy would a 20lb dog running at 4m/s have?
The formula for kinetic energy is 1/2m X V2. The dog would have 160J of kinetic energy.
Joules
A hair dryer transforms electrical energy into (this kind of energy) and (this kind of energy)
Thermal (heat) and sound.
What form of energy that occurs when a cyclist is pedaling or a soccer player is kicking the ball?
Mechanical Energy
What is the difference between energy transfer and and energy transformation? Give an example of each.
Energy transfer is the movement of the same type of energy from one location to another. Energy transformation is when energy changes from one type to another. Energy transfer is when a bowling ball hits the pins. Energy transformation is when the you turn on the lights in the bowling alley and the electrical energy in turns into radiant and thermal energy in the lights.
How do you calculate gravitational potential energy? How much gravitational potential energy does a 5lb ball at the top of a 6m ramp have?
The formula for gravitational potential energy is weight (mass gravity) x height. GPE=mgh.
A 5lb ball at the top of a 6m ramp has 294J of gravitational potential energy. (5lbs x 6m x 9.8m/s).
What are two variables that increase kinetic energy?
Mass and speed
What type of energy transformation happens in photosynthesis?
If an animal eats the plant and hops away, what kind of energy transformation happens?
In photosynthesis, electromagnetic energy from the sun is converted to chemical energy.
If an animal eats the plant and hops away, chemical energy from the plant is converted to kinetic (or mechanical) energy.
What is the difference between nuclear fusion and nuclear fission?
Fission is the splitting of a nucleus into two lighter nuclei, and fusion is the process where two light nuclei combine together releasing vast amounts of energy.