FT - 16 Earth and Beyond
Q1.
A school is near a busy road. A car travels past
the school at high speed.
The students notice that the sound of the car
engine seems to change as the car travels past the
school. A teacher says that this is an example of
the Doppler effect. The students decide to study
the sound they hear from passing cars.
(a)
(i)
Give one risk the students should
consider when doing their study.
...............................................................................................................
(1)
(ii)
As a car travels towards the students, the frequency of the sound the students hear
is different to the frequency of the sound they would hear if the car was stationary.
Draw a ring around the correct answer in the box to complete the sentence.
decreased.
Compared to the sound from the stationary car, the frequency has
increased.
become quieter.
(1)
(b)
In the same way as the sound from the car engine changes, the light from most galaxies also seems to have
a change in observed frequency. This is called red-shift.
(i)
The diagram shows four galaxies, P, Q, R and S. The arrows show the direction the galaxies are
moving relative to the Earth.
Which one of the galaxies is moving the fastest?
Write the correct answer in the box.
Which one of the galaxies will produce the biggest red-shift?
Write the correct answer in the box.
(
(ii)
Most scientists support a theory that the Universe began from a very small initial
point. Red-shift can be used as evidence for this theory.
What name is given to the theory that the Universe began from a very small initial
point?
........................................................................................................................
(1)
(iii)
Cosmic microwave background radiation (CMBR) provides more evidence for this theory. CMBR is
detected coming from space.
Where does CMBR come from?
Tick (
) one box.
CMBR only comes from near the Sun.
CMBR comes from all parts of the Universe.
CMBR only comes from the Moon.
(
(iv)
Which statement gives the reason why most scientists support the theory that the
Universe began from a very small initial point?
Tick (
) one box.
The evidence proves it happened.
There is no other way of explaining how the Universe began.
At the moment it is the best way of explaining our scientific knowledge.
(1)
(Total 7 marks)
HT - 16 Earth and Beyond
Q2.
A police officer uses a radar gun to check the speed of cars. The radar gun emits a beam
of microwaves. The microwaves are reflected by the moving car.
The reflected microwaves have a different frequency to the microwaves that are emitted by the
radar gun. This change in frequency can be used to determine the speed of the car as it moves
towards the police officer.
(a)
What is the name given to the observed change in frequency of the microwaves?
........................................................................................................................
(1)
(b)
(i)
How is the wavelength of the reflected microwaves different from the wavelength of
the microwaves emitted by the radar gun?
........................................................................................................................
(1)
(ii)
The speed of the microwaves emitted by the radar gun is 300 000 000 m/s.
What is the speed of the reflected microwaves?
........................................................................................................................
(1)
(c)
A car is travelling in an area where the speed limit is 70 km/hour.
The frequency of the microwaves emitted by the radar gun is 27 000 000 kHz.
The frequency of the reflected microwaves is 27 000 004 kHz.
The graph shows the relationship between the speed of a car and the observed change in
frequency of the microwaves.
(i)
Is the car exceeding the speed limit? Use information from the data given and the
graph to explain your answer.
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
(2)
(ii)
The police officer determines the speed of a different car. The frequency of the
microwaves emitted by the radar gun is 27 000 000 kHz.The reflected microwaves
have a frequency of 26 999 998 kHz.
What is the speed and direction of this car? Show clearly how you work out your
answer.
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
(3)
(Total 8 marks)
M1.
(a)
(i) any suitable risk
eg being injured by a car
accept a measure to reduce the risk eg
stand well away from edge of pavement
stay on school grounds / don’t go onto the street
be aware of the dangers of traffic
car travelling at high speed is insufficient
1
(ii)
increased
1
(b)
(i)
S
1
S
1
(ii)
big bang (theory)
1
(iii)
CMBR comes from all parts of the Universe
1
(iv)
At the moment it is the best way of explaining our scientific knowledge
1
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M2.(a)
Doppler (effect / shift)
do not allow red shift
do not allow blue shift
1
(b)
(i)
shorter / decreased
allow smaller
allow radar gun wavelength is longer
ignore reference to speed / frequency
ignore closer together
1
(ii)
the same / 300 000 000 (m/s)
accept 3 × 108 (m/s)
accept 300 000 km/s
1
(c)
(i)if answer ‘not speeding’ = 0 marks
implication that the car is speeding needed to gain 2 marks
(speed =) 80 (km/hour) so speeding
or
10 (km/hour) above speed limit
if no reference to speeding allow 1 mark for 80 (km/hour)
if say speeding and 4(kHz) and 80 (km/hour) shown on
graph = 2 marks
if no reference to speeding 4(kHz) and 80 (km/hour) shown on
graph = 1 mark
or
change in frequency 3.5 kHz at 70 km/hour (1)
(observed change in frequency =) 4 (kHz) so speeding / 80 km/hour (1)
2
(ii)
40 (km/hour)
accept (observed change in frequency =) (–)2 (kHz) for 1 mark
2
away from (police officer / radar gun)
allow reversing
or
in opposite direction to other car
1
[8]