Energy Flashcards
Name 4 energy stores
magnetic, kinetic, heat (thermal), gravitational, electrostatic, chemical, elastic, electrical, nuclear
Describe the energy transfers that occur as a ball falls to the ground.
gravitational potential -> kinetic
State the equation for finding the energy in an object’s kinetic energy store
Ek = ½ × m × v2
If energy is transferred to an objects kinetic energy store, what happens to its speed?
the speed increases
State the equation for finding the energy in an object’s gravitational potential energy store
GPE = mgh
What kind of energy is stored in a compressed spring?
Elastic potential energy
State the conservation of energy principle
Energy is never created or destroyed. Only changed from one form to another
Define power and give an equation to calculate power
P=E/t. It is the rate of which energy is transferred
What are the units of power?
Watts (W)
How can you reduce unwanted energy transfers in a machine with moving, touching components?
Use lubricants (like oil)
True or false? A high thermal conductivity means there is a high rate of energy transfer
True
Give 4 ways to prevent unwanted energy transfers in a home
Cavity wall insulation, loft insulation, double-glazed windows, closing doors / windows
True or false? Thicker walls make a house cool down quicker
False
State the equation that relates efficiency to power.
Efficiency=useful power output / total power in
Name 4 renewable energy resources
solar, wind, hydroelectric, wave, tidal
