aqa physics - changes in energy

what type of energy does a moving object have?

kinetic energy

what happens to kinetic energy when an object speeds up or slows down?

it increases when an object speeds up and decreases when it slows down

what two factors affect the amount of energy in an object's kinetic energy store?

mass and speed

what is the word equation for kinetic energy?

kinetic energy (j) = 0.5 x mass (kg) x speed² (m/s²)

what type of energy is stored in raised objects?

gravitational potential energy

what happens when you lift an object in a gravitational field?

energy is transferred to the object's gravitational potential energy store

what three factors affect the amount of gravitational potential energy an object has?

mass, height, and gravitational field strength

what is the word equation for gravitational potential energy?

g.p.e = mass (kg) x gravitational field strength (n/kg) x height (m)

how is energy transferred when an object falls?

energy moves from the gravitational potential energy store to the kinetic energy store

what happens to energy when a falling object has no resistance?

all energy lost from the gravitational potential store is gained in the kinetic energy store

how does air resistance affect falling objects?

it transfers some energy to other stores instead of all of it going to the kinetic energy store

how is energy transferred to an elastic potential energy store?

by stretching or squashing an object

when can you use the elastic potential energy equation?

when the object has not exceeded the limit of proportionality

what is the word equation for elastic potential energy?

elastic potential energy (j) = 0.5 x spring constant (n/m) x extension² (m)