Unit 1, energy Flashcards
(70 cards)
What is the formula for kinetic energy
1/2 x mass x speed2
What is the formula for GPE
Mass x gravitational field strength x height
What is the formula for power
Power = work done/time taken = energy transferred/time taken
What are the formulas for efficiency
Efficiency = useful energy output/ total energy input
Efficiency = useful power output/total power output
What is the formula for elastic potential energy
Elastic potential energy = 0.5 x spring constant x (extension)2
What is the formula for change in thermal energy
Change in thermal energy = mass x specific heat capacity x temperature change
What is the unit for energy
Joules
What is the unit for mass
Kilograms
What is the unit for speed
Metres per second
State the principle of conservation of energy
Energy cannot be created or destroyed but only transferred from one store to another
What is the unit for gravitational field strength
Newtons per kilogram
What is the unit for power
Watts
What is the unit for specific heat capacity
J/kg*c
Unit for spring constant
N/m
What is the definition for power
Power is the rate of transfer of energy or the rate of doing work
What is the unit for work done
Joules
List 8 energy stores
chemical, kinetic, gravitational potential, elastic potential, nuclear, magnetic, electrostatic, thermal
Energy stored in objects which move is…
Kinetic energy
How can you reduce unwanted energy loss in a machine with moving/touching parts?
Use oil/lubricant
A battery is a store of __________ energy.
chemical
Food is a store of __________ energy.
chemical
What can you do to increase a particular object’s kinetic energy store?
Move it faster
What can you do to increase a particular object’s gravitational potential energy store?
Lift it higher
A rock at the top of a hill is a store of ___________ energy.
Gravitational potential