Physics Paper 1

Front 1

how is speed calculated

Back 1

speed(m/s)=distance(m)/time(s)

time= distance/speed

Front 2

what does the gradient of a distance-time graph represent

Back 2

speed

the steeper the gradient the greater the speed

a horizontal line represents stopped (no increase in distance)

Front 3

what is velocity

Back 3

speed in a direction

it is a vector quantity

measured in m/s

Front 4

what is acceleration

Back 4

the rate of change in a given direction

measured in m/s2

accleleration = change in velocity/ time taken for change

Front 5

what are the key features of a velocity-time graph

Back 5

are under the line= distance travelled(m)

gradient = acceleration

the steeper the gradient the greater the acceleration

horizontal line means constant velocity

unless the line is on the x-axis: means stopped

Front 6

what can forces do to an object?

Back 6

change its shape

change its motion

(nb forces cause a change in motion-an object does not need force on it to be moving)

Front 7

unbalanced forces result in

Back 7

a resultant force

an acceleration (change in motion)

f(n)= mass(kg)*acceleration(m/s2)

mass= force/acceleration

acceleration = force/mass

Front 8

balanced forces result in

Back 8

no acceleration (no change in velocity)

Front 9

stopping distance is

Back 9

thinking distance + breaking distance

nb: be careful to check whether the question discussing stopping distance or stopping time

Front 10

factors whihc affect the thinking distance are

Back 10

related to the driver:tiredness, drugs, distractions

speed of the car (does not affect the time just the distance travelled while thinking)

Front 11

factors which affect the stopping distance are

Back 11

related to the car & conditions: weather, ice, effectiveness of the breaks

speed of the car (does not affect the time just the distance travelled while stopping)

Front 12

what is the difference between weight and mass?

Back 12

weight is force caused by gravity acting on a mass

mass is a measure of the number of particles in an object

weight(n)= strength of gravityn/kg)*mass(kg)

Front 13

what are the forces on a falling object

Back 13

weight (down) and drag(up)

Front 14

why do falling objects reach a terminal velocity

Back 14

as objects fall they accelerate. their weight stays the same but as they move faster the drag increases.

the resultant forces reduces and so acceleration reduces

eventually the drag force is equal and opposite to the weight (forces are balance)

there is no acceleration this speed is terminal velocity

Front 15

how is extention calculated

Back 15

extension=length- original length

Front 16

what type of energy is stored ina spring

Back 16

elastic potential energy

Front 17

hat is hookes law

Back 17

relates the force applied to a spring to its extention

force(n)=spring constant (n/m)*extension(m)

spring constant = force /extension

the relationship between force and extension os directly proportional (a straight line on a graph through the origin_

Front 18

what is energy? how is it measured

Back 18

energy is the ability to work

it is measured in joules

Front 19

how much energy is used moving on an object

Back 19

energy transferred=work done

work done(j)=force*distance(m)

force=work done/distance

Front 20

how much energy is used moving an object upwards

Back 20

change in gpe(j)=weight (n)*change in height (m)

change in gpe (j)= mass (kg) strength of gravity (n/kg) * change in hight

Front 21

how is power related to energy

Back 21

rate of energy transfer

power=energy/time

Front 22

how is kinetic energy calculated

Back 22

ke= 0.5*mass*velocity2

mass=2xke/veloctiy

Front 23

what is momentum

Back 23

a vector quantity related to the mass&velocity of a moving object

momentum = mass *velocity

Front 24

what is the law of conservation of momentum

Back 24

in a closed system

momentum before an event=momentum after an event

usually applied in collisions

Front 25

how does safety features such as helmets/rubber matting/ air bags work

Back 25

reduce the impact force

for the same energy transfer/change in momentum

increasing the distance/time over which the energy is transferred

reduces the force

force=energy/ distance

force= change in momentum/ time taken

Front 26

how is static electricity formed

Back 26

use of a force such as friction

to separate charges in an insulator (they can't flow and recombine in an insulator)

Front 27

what do opposite/ like charges do?

Back 27

opposite charges attract

like charges repel

Front 28

what is an electric current

Back 28

the flow of charge

Front 29

what flows through a circuit

Back 29

electrons (electric charge)

Front 30

how is current related to charge flow?

Back 30

curent(a)=charge flow(c)/time(s)

charge=current*time

time=charge flow/current

Front 31

how are ammeters and voltmeters connected in a circuit

Back 31

ammeters in series

voltmeters in parallel

Front 32

what is resistance

Back 32

a measure of how difficult it is for a charge to flow through a component

measured in Ohms

resistance+voltage/current

Front 33

how are charge, voltage and energy related?

Back 33

voltage=work done/charge

Front 34

what is unusual about a diode?

Back 34

only lets current through it in one direction

needs about 0.7v before any current flows

Front 35

what are the properties of a thermistor?

Back 35

resistance decreases with temperature

Front 36

what are the proporties of ldr

Back 36

resistance decreases with ligt

Front 37

what are the properties of a filament lamp

Back 37

resistance increases with current/temperature

this is because ions in the metal vibrate more at higher tempratures so it is harder for the charge to flow through

Front 38

what are the rules of a series circuit

Back 38

current is the same at all points in the circuit

volatage is shared across the components

Front 39

what are the rules for parallel circuits

Back 39

each loop has the full voltage

current is shared across the loops