Science Forces and energy Flashcards
(36 cards)
What is energy?
The ability to do work
What is the law of conservation of energy
Energy can’t be created or destroyed, it can only be transformed
What is potential energy
Energy due to its position
What is kinetic energy
Energy to its motion
What are 3 types of kinetic energy
Heat, sound and light energy
What is heat energy
Found in hot objects
What is sound energy
Air particles in the form of a wave to your ear
What is light energy
Travels from source to your eye
What is electrical energy
The flow of tiny particles called electrons
What are 3 types of potential energy
Gravitational, elastic and chemical energy
What is gravitational potential energy
An object experiencing gravity; every object on earth has GPE because everything is attracted to the earth’s centre
What is elastic potential energy
Energy gained when objects are stretched
What is chemical potential energy
Energy stored when atoms and molecules bond, can be found in food
What is efficiency
Term to describe how well it does its job and how little energy is required to do that job
How do you find efficiency
Efficiency = useful energy output (j) divided by total energy input (j)
x 100
What is the input energy of a lightbulb
Electrical
What is the useful energy of a lightbulb
Light
What is the waste energy of a lightbulb
Heat
What are forces
A push or pull when two objects interact
What are the 2 types of forces
Contact and non-contact
What are balanced forces
2 forces equal in size but opposite in direction
What are unbalanced forces
2 or more forces unequal in size and direction
What are the forces in a pile of books on a table
Normal force and weight
What are the forces in a boy kicking a ball
Applied force, normal force, weight, friction
