Topic 1 Conservation and Dissipation Flashcards
Describe and give Examples on Chemical Energy Store
The energy stored in chemical bonds
between molecules. Example: Food, Cells, Fuel, Muscles
Describe and give Examples on Kinetic Energy Store
The energy of moving objects. Examples: Runners, Buses
Describe and give Examples on Gravitational Potential Energy Store
The energy of an object at height. Examples: Aeroplanes, Mugs on a table, Basketball
Describe and give Examples on Thermal (internal) Energy Store
The total Energy of particle in the object. Examples: Hot Coffee, Hot Food
Describe and give Examples on Elastic Potential Energy Store
The energy stores when an object is stretched or squashed. Examples: Elastic Band, Plastic Bags
Describe and give Examples on Magnetic Energy Store
The energy stored when repelling poles
have been pushed closer. Examples: Fridge Magnets, Compasses
Describe and give Examples on Electrostatic Energy Store
The energy stored when repelling charges
have been moved closer. Example: Van de Graaff generator
Describe and give Examples on Nuclear Energy Store
The energy stored in the nucleus of an
atom. Examples: Nuclear Reactors
What is conservation of energy?
Energy cannot be created or destroyed, it can only be transferred from one store to another
What does work mean (in terms of physics)?
In Physics, working means the amount of energy transferred when a force moves (in the direction of the force)
What is the calculation for work?
W (Work [J]) = F (Force [N]) x s (Distance [m])
What is friction and how does this affect work done?
Friction is an opposing force to direction of movement when two surfaces are in contact The work is done against frictional force
How do the energy stores change?
When the brakes are applied to stop the wheel, the kinetic energy store transfers energy to the thermal energy store of the brake pads and discs. These become hot and transfer energy by heating to the surroundings.
Explain the changes in energy stores a meteorite enters the Earth’s atmosphere (including the role friction has in this process).
Kinetic energy: As the meteor accelerates due to gravity, the gravitation potential energy decreases and is converted into kinetic
Gravitation Potential Energy: The meteorite initially has a high gravitational potential due to its position in the Earth’s gravitational field.
Thermal Energy: the meteorite and air particles generates heat. This converts kinetic energy into thermal.
Light Energy : The intense heat causes the meteorite to glow, or emitting light as it burns up during descent
What is the formula for Gravitational Potential Energy
(Delta Triangle) Ep = m x g x (Delta) h
What is the calculation for Kinetic Energy
Kinetic Energy = ½ x mass x velocity^2
Ek = Kinetic energy (Joules, J)
m = mass (Kilograms,kg)
V = velocity(m/s)
What is the calculation Elastic Potential Energy?
Elastic potential Energy (Ee) = ½ x k x e2
Ee = Elastic potential energy (Joules, J)
k= spring constant(N/m)
e= extension(m)
Define Useful Energy
Useful energy is energy transferred to where it is wanted and in the form it is wanted.
Define Wasted Energy
Wasted energy is energy that is not usefully transferred.
What is the calculation for efficiency?
energy efficiency = useful output energy divided by total input energy
