IGCSE Physics ### CIE IGCSE Physics Solved Past Paper May/June 2020 P43

b i) constant acceleration

ii) increasing acceleration

iii) deceleration

iv) constant speed

2a) mass = density*volume

Volume = 0.3*0.3*0.4=0.036m3

Mass = 1020*0.036=37kg

b i) pressure due to depth = 500k-100k=400k Pa

Depth = pressure/density*gravity

=400000/1020*10

=39m

ii) force = pressure*area

= 500k*0.62

= 3.1*10^4N

3a) line of action of center of mass falls out of base of bus

b) less stable as center of mass of bus falls out of base of bus

c i) mass of passengers = 73*65=4745

Total mass = 4745+1600=21000kg

ii) force = mass*acceleration

20745*14/20

= 15000N

4a) more energetic molecules escape from the surface leaving behind less

energetic molecules.Average kinetic energy of liquid decreases and as a

result temperature of remaining liquid drops

b) more wind, higher temperature of air

5 ai)  energy = power*time

= 50*2*60

= 6000J

ii)   specific heat caoacity = 6000/0.55*13

= 840J/kg ?

iii) some heat from heater lost to surroundings so actual value might be

lower

b) water has higher specifi heat capacity and since same rate of energy

is supplied to both sand and sea,increase in temperature is not as much

that of the sand

6a) with normal perpendicular to surface, angle of incidence = angle of

reflection

c) 1500m/s

7a) angle of incidence = angle between normal and the incident ray

So angle of incidence = 90-40=50

Refractive index = sin i/sin r

Sin r =sin i/n

r = sin-1(0.32) = 18

b) when all the light travelling from an opticall denser medium to an

optically rarer medium is  reflected for which the angle of incidence is

greater than the critical angle

c) light reflected from surface one as angle of incidence is greater than

critical angle light from surface 2 bends away from normal as it is

Travelling from a denser to rarer medium

8 ai) electric field is the area where a charge experiences a force

ii) it is the direction of chage on a positive charge

b) the ball after moving first touches either of the plates in case it touches

the positive plate, it gains positive charge through the layer of

conducting metal on its surface. It is then repelled away from the

positive plate and towards the negative plate.

c) charge = current*time

time = charge/current

= 15/0.29 = 52 seconds

9 ai) in this question fleming’s left hand rule is applied so by having the

pointer finger, middle finger and the thumb in perpendicular positions

to each other, pointer indicates magnetic field with the middle finger

indicating the conventional current direction, the thumb represents

Direction of force, which is downward on left side of coil.

This means the coil turns anti-clockwise

ii) from negative to positive terminal

iii) electrons repelled from the negative terminal of supply

b i)  turns in opposite direction

ii) turns faster

iii)  turns faster

10 ai) beta particle

b i) background radiation of rocks

ii) 11400/5700 = 2 half lives have passed so that means after subtracting

background radiation from 80 and 20, counts are 70 and 10.

This means that if statement of question is right, after reducing 70 by

half, twice(because two half lives) the amount should be around 10 but:

70/2=35/2=17.5>10 as this amount is greater than that suggested by

question, this means that age of sample is more than 11400 years as it

needs more than just 2 half lives to decrease from 70 to 10.