mistake log

why does GPE decrease when an object falls over?

centre of gravity is lower

when do you draw a bar graph instead of line?

data is discrete/discontinuous - this basically means when you can’t have a half (eg number of rubber bands or colour)

HOWEVER edexcel are ragebaiting so sometimes they want a line just have a look at the surrounding questions to get a gist of what they want now (so demanding of them)

suggest why uranium-238 is the most common isotope of uranium

has the longest half life

describe what happens in a nuclear reactor when a control rod is removed

rate of reaction increases

fewer neutrons absorbed by control rod

temperature increases

explain why it is difficult to make the surrounding area safe again after a serious nuclear incident

radiation is dangerous to life - causes mutation and can kill

high activity levels

long half-life

difficult for workers to access (short working times, need protective clothing)

stays radioactive for a very long time

need special handling equipment

radioactive material mixes with the soil/water

why do planets nearer the sun take less time to orbit?

closer planets have a faster orbital speed

describe the motion of the particles when a metal is a gas

random, high speeds

random directions

state one use of radioactive isotopes

smoke alarms

what type of wave is a water wave?

transverse

which radioactive isotopes would cause the biggest risk to health BASED SOLEY ON HALF LIVES?

shortest half life

highest activity

if it says something is travelling at a constant speed what are we going to remember when drawing the arrows?

they must be equal length

state two electrical safety features that can be used in mains-operated domestic appliances (do not say a fuse)

double insulation

clips (to stop you pulling the wire out)

explain why the coil of wire heats up when there is a current in it

groups of electrons with EPE travel through atomic lattice of wire

they collide with some of these atoms, transferring them energy and making them speed up/vibrate more

increase in KE causes wire to heat up

coil has resistance

give the name of the variable that is measured on the x-axis of the oscilloscope screen

time

explain how a convection current forms in the tank of water

the hot, less dense water rises

cools at the top, becomes more dense and sinks

why is plastic foam good at reducing heat loss through the walls

blocks/traps the air with a solid

this prevents convection

air is a good insulator

explain what happens to the braking force as the train decelerates, using a graph given to you

gradient is decreased after (time)

so deceleration decreases

so braking force decreases

are we going to write down the correct numbers from our calculator

of course silly

explain how drinking alcohol would affect the stopping distance of the train

increased reaction time

thinking distance = reaction time x speed, so it increases

stopping distance = thinking distance + braking distance, so stopping distance increases