5 - Work, energy and power Flashcards
What is kinetic energy?
Energy due to motion of an object with mass.
What is Gravitational Potential Energy?
Energy of an object due to its position in a gravitational field.
What is Chemical Energy?
Energy contained within the chemical bonds between atoms - it can be released when atoms are rearranged.
What is Elastic Potential Energy?
Energy stored in an object as a result of reversible change in its shape.
What is Electrical Potential Energy?
Energy of electrical charges due to their position in an electric field.
What is Nuclear Energy?
Energy within the nuclei of atoms - it can be released when the particles within the nucleus are rearranged.
What is Radiant (or electromagnetic) energy?
Energy associated with all electromagnetic waves, stored within the oscillating electric and magnetic fields
What is Sound Energy?
Energy of mechanical waves due to the movement of atoms
What is Thermal energy?
The sum of the random potential and kinetic energies of atoms in a system.
Give two examples of kinetic energy.
Moving car
Moving atoms
Give two examples of gravitational potential energy.
Child at the top of a side
Water held in clouds
Give two examples of chemical energy.
Energy stored within a chemical cell
Energy stored in petrol and released when it is burnt
Give two examples of elastic potential energy.
A stretched guitar string
A squashed spring
Give two examples of electrical potential energy.
Electrical charges on a thundercloud
Static charge on a charged balloon
Give two examples of nuclear energy.
Energy from fusion processes in the Sun
Energy from nuclear fission reactors
Give two examples of radiant energy.
Energy from the hot sun
Energy from an LED
Give two examples of sound energy.
Energy emitted when you clap
Output energy from your headphones
Give an example of something with a lot of thermal energy.
A hot cup of tea.
What is the unit for work done?
The Joule
What is energy?
The capacity for doing work.
What is the principle of conservation of energy?
The total energy for a closed system must remain constant.
Energy can neither be created or destroyed, only transferred from one form to another.
What is work done?
Energy that is transferred by a force.
What does the term “potential” mean in physics?”
Hidden or stored.
What is the equation for kinetic energy?
KE = ½ mv^2
What is the equation for gravitational potential energy?
GPE = mgh
Define power.
Power is the rate of transfer of energy.
WHAT is the unit of power..?
Watts
How do you calculate the power of a moving object?
Force x velocity
What is efficiency?
The proportion of the total energy that is transferred by a device that is transferred to useful energy.
(useful/total x 100)
