Work, power and efficiency Flashcards
(13 cards)
What is work done?
Work done is when a force moves an object by a certain distance.
How do you define 1 joule?
1 joule is the equivalent of 1N of force moving an object by 1m
What is the kinetic energy store of an object?
The kinetic energy store of an object relates to the object’s motion. Furthermore an object’s mass also affects kinetic energy.
What is the elastic potential energy store of an object?
The elastic potential energy of an object is related to how stretched it is - the more stretched the more elastic potential energy.
What is the gravitational potential energy store of an object?
The gravitational potential energy store of an object is related to how high above the earth’s surface it is - the higher it is the more energy.
What is power?
Power is the rate of energy transfer or work done.
How do you define 1 watt?
1 watt is equivalent to 1 joule being transferred per second.
What is the value of gravity of earth?
9.8 Newtons
What is the value of gravity on the moon?
1.6 Newtons
What is the law of conservation of energy?
The law of conservation of energy is the idea that energy cannot be created or destroyed, only transferred and stored.
How do we apply the law of conservation of energy?
The total amount of input energy is equivalent to the total amount of output energy.
What does it mean if a device is efficient?
If a device is efficient then it transfers energy usefully.
What does it mean if a device is inefficient?
If a device is inefficient then it transfers energy to it’s surroundings, we call this wasted energy as it is transferred to less useful stores.
