P1 Flashcards
Energy can only be….
Transferred, it can’t be created or destroyed
What is the equation for work done?
Force x Distance
What is the equation for gravitational potential energy?
Mass x Gravitation fields strength (9.81 on earth) x height
What is the equation for kinetic energy?
1/2 x mass x (speed^2)
What is the equation for elastic potential energy?
1/2 x spring constant x extension^2
What is the equation for energy efficiency?
Useful energy/ total energy x 100
Name one way machines can lower waste energy…
Adding lubricants to reduce friction or installing thermal insulation
What is one Watt equal to?
1 J/s
Name the main energy types?
Kinetic Thermal Sound Light Chemical GPE Elastic potential Nuclear
How do you calculate wasted energy/power?
Total energy/power - useful energy/power
What is hookes law?
Force is directly proportional to the extension of a spring until it reaches its elastic potential.
What happens to wasted energy such as heat energy in a car engine?
It gets dissapated.
What is the input energy?
The energy supplied to the device.
Why can you not get over 100% efficiency?
You can’t end with more energy than you started with as energy can’t be created.
What is one of the most efficient electrical appliance that you could have?
A heater or a radiator
What type of energy is food energy?
Chemical energy
What is kinetic energy?
Energy transferred through movement.
What is the unit of power?
W
What is the unit of energy?
J
What is the unit of mass
Kg
What is the unit of time?
Seconds (s)
Is work done equal to energy?
Yeah courssseeeee
What is the equation for force applied to a spring
Force applied to a spring(N) = spring constant (N/m) x extension (m)
What is a system
An object or group of objects
