P1, Energy

Question 1

describe the energy transfers that occur as a ball falls to the ground

Answer 1

A ball dropped from a height is accelerated by gravity - the gravitational force does work
This causes energy to be transferred from the ball’s gravitational potential energy store to it’s kinetic energy store

Question 2

if energy is transferred to an object’s kinetic energy store, what happens to its speed?

Answer 2

it increases

Question 3

what kind of energy is transferred when you compress a string

Answer 3

elastic potential energy

Question 4

what does work mean

Answer 4

energy transferred

Question 5

what happens when someone throws a ball upwards

Answer 5

• the initial force exerted by the person to throw the ball upwards does work
• causes an energy transfer from the chemical energy store of the person’s arm to the kinetic energy store of the ball and arm

Question 6

what are closed systems

Answer 6

systems where neither matter nor energy can enter or leave

Question 7

what is a system

Answer 7

a single object (e.g the air in a piston) or a group of objects (e.g 2 colliding vehicles)

Question 8

what happens when a system changes

Answer 8

energy is transferred into or away from the system between different objects in the system pr between different types of energy stores

Question 9

what happens when a person boils a kettle

Answer 9

energy is transferred into the water’s thermal energy store by heating, causing thr temperature of the water to rise

Question 10

what is specific heat capacity

Answer 10

amount of energy needed to raise the temperature of 1kgof substance by 1 degree

(how hard it is to heat something up)