Energy
Q 3.1
solar
allow biofuel / biodiesel
allow wave power
Q1.1
What is V=IR?
Explain why heating a gas increases the average speed of the gas particles
Heating a gas increases its temperature [1].
The temperature is proportional to kinetic energy [1].
If the kinetic energy of a gas increases then the speed of the gas particles increases [1].
Q 2.2
the atom becomes a positive ion (1)
the atom loses an electron (1)
Q 4.1
zero error
allow systematic error
Q 3.2
sometimes there is no wind (but the battery can still be charged using the generator) (1)
when there is wind less fuel is burned (1)
Q1.3
What is E=Pt?
Tricked Ya!! It is electricity
Q 5.3
potential difference is (directly) proportional to current
Q 2.3
beta radiation is only weakly ionising
Q 4.3
resolution
Q 6.1
latent heat (of vaporisation)
*allow specific latent heat (of vaporisation)
Q1.4
(3 marks- show 3 steps)
time = 150 000s
energy = 0.46 × 150 000
energy = 69 000 (J)
Q 4.5
add several coins to the measuring cylinder (1)
measure the change in the water level in the measuring cylinder (1)
divide by the number of coins added (1)
Q 2.1
1 more than 10 000 times bigger
Q 4.2
reset the balance to zero g
allow subtract the reading shown on the balance from the reading taken
Q 6.6
the advertisement has ignored the energy input from the surrounding air
so the total energy input is greater than the energy supplied from the electricity
the efficiency must be less than 100%
Q 3.4
81 kJ = 81 000 J
81000 = 0.5 × 8000 × v2
v = SqR ( 81 000 0.5 × 8000 v)
= 4.5 (m/s)
Q 4.6
8.9 = 3.6 area × 0.16 (1)
area = 3.6 8.9 × 0.16 (1)
density = 3.6 2.528 × 0.17 (1)
density = 8.37… (g/cm3) (1)
density = 8.4 g/cm3 (1)
Four atoms have the numbers of protons and neutrons given below. Which two atoms are isotopes of the same element?
W: 8 protons and 8 neutrons
X: 8 protons and 10 neutrons
Y: 10 protons and 8 neutrons
Z: 9 protons and 10 neutrons
W and X
Q 4.4
place the measuring cylinder on a horizontal surface (1)
view with eye in line with the level of the water (1)
*allow read from the bottom of the meniscus
Q 6.5
0.875 = useful output energy transfer/1 560 000
useful output energy transfer = 1 365 000(J)
365 000 = 125 × c × (22.1–11.6)
c = 1 365 000 / (125 × 10.5)
c = 1040 (J/kg °C)
c = 1.04 × 103 (J/kg °C)
Q 5.2
because the potential difference is always positive
*allow because potential difference does not change direction
Read thoroughly.
There is solid ice on a car’s rear window.
The glass window contains an electrical heating element.
Use the particle model above to describe how the heating element causes the arrangement of the ice particles to change as the ice melts.
You should include a description of how the particles are arranged in the solid ice and in the water. [6 marks]
A strong answer will be clearly worded with good use of scientific key words. It may include the following points:
Solid:
Melting:
Liquid:
[6]
Q 2.4
Indicative content
• move the detector very close to the source
• record the count rate
• position the paper between the source and the detector
• record the new count rate
• alpha radiation will not penetrate through paper
• if the count rate with the paper is (significantly) less than without then the source emits alpha radiation
• remove the paper and position the aluminium between the source and the detector
• record the new count rate
• (alpha and) beta radiation will not penetrate through the aluminium
• if the count rate has (significantly) reduced compared with using paper then beta radiation is present
• if radiation penetrates through the aluminium then gamma radiation is present
• the experiment should be repeated and mean results calculated because radioactivity is a random process
To access level 3, the candidate must use the paper sheet, the aluminium sheet and no sheet, and describe how the results would indicate the presence of alpha, beta or gamma radiation.
Define Precision and Accuracy.
Precise - A group of measurements with a small range
Accurate - How close a measurement is to the true value