P P1 - Energy Flashcards
What is a closed system?
A closed system is when energy cannot escape, so there is no change in the total energy in the system
What is an open system?
An open system is when energy can dissipate
How do you calculate work done?
Work done = force x distance
What does it mean when work is done?
Work is done when an object moves and energy is transferred
How can you reduce friction?
Friction can be reduced by using wheels, applying lubrication
How can you reduce air resistance?
Air resistance can be reduced by travelling slowly and streamlining
What is the law of conservation of energy?
The law of conservation energy is when energy can be transferred, but not created or destroyed
What are ways that wasted energy can be reduced?
Wasted energy can be reduced by insulation, streamlining, lubrication of moving parts
What happens to wasted energy?
Wasted energy dissipates into the surroundings as thermal energy
How can efficiency be increased?
Efficiency can be increased by using machines
What is specific heat capacity?
Specific heat capacity is the amount of energy required to raise 1kg of a substance by 1 degree
What does specific heat capacity depend on?
Specific heat capacity depends on the mass of a substance, what the substance is, and the energy put into the system
How do you calculate the change in thermal energy?
Change in thermal energy = mass x specific heat capacity x temperature change
What are the ways in which energy can be transferred?
Energy can be transferred through light, sound, electricity, thermal, kinetic
What is kinetic energy?
Kinetic energy is the energy stored by a moving object
What is elastic potential energy?
Elastic potential energy is the energy stored in a stretched spring, elastic band
What is gravitational potential energy?
Gravitational potential energy is the energy gained by an object when raised above the ground
How do you calculate kinetic energy?
Kinetic energy = 1/2 x mass x velocity (squared)