Energy Basics
The ability to do work or cause change.
What is energy?
Energy cannot be created or destroyed, only transformed or transferred.
What is the Law of Conservation of Energy?
The type of energy stored in food.
Chemical energy
A system where energy cannot enter or leave—only changes form within it.
What is a closed system?
The potential energy on a roller coaster is the greatest at which point?
At the highest point of the track
The two main types of energy
What are potential and kinetic energy?
In a closed system, the total energy ___________.
stays the same or is conserved.
The energy transformation that occurs when you are riding a bike.
Chemical → mechanical (kinetic).
A system where energy can enter or leave.
What is an open system?
The kinetic energy on a roller coaster is the greatest at which point?
At the lowest point of the track.
The type of energy stored due to an object’s position or height
What is potential energy?
A ball is dropped from a height of 5 feet. Describe how its energy changes as it falls.
Potential energy decreases while kinetic energy increases.
The energy transformation that occurs when using a flashlight.
Chemical → electrical → light (and heat).
A sealed thermos keeping soup hot is an example of what type of system.
What is a closed system?
If energy cannot be created or destroyed, explain why a moving skateboard eventually stops rolling.
Some of the skateboard’s kinetic energy is transformed into heat and sound due to friction with the ground, but the total energy is still conserved.
The type of energy associated with motion
What is kinetic energy?
Explain why a ball does not bounce back to its original height.
Some energy is transferred to sound and heat—still conserved but transformed.
The energy tranformation that occurs when using a microwave.
Electrical → electromagnetic (radiation) → thermal.
A pot of boiling water losing steam and heat to the air is an example of what type of system?
An open system.
Describe what happens to total energy when a moving car slows down due to friction.
Kinetic energy decreases but transforms into thermal energy; total energy is conserved.
The total energy of motion in the particles of a substance.
What is thermal energy?
How does friction show energy conservation?
It transforms motion energy into heat, keeping total energy constant.
What transformation happens in a car engine?
Chemical (fuel) → mechanical + heat energy.
How can you make an open system more closed?
By adding insulation or reducing heat transfer to the surroundings.
What type of energy transformation happens when you rub your hands?
Mechanical energy transforms into thermal energy (heat).