Physics Paper 1 specimen paper

Question 1

1. there are many different types of waves
   a) waves on the surface of water are transverse waves. sound waves are longitudinal waves.

describe the difference between transverse and longitudinal waves

Answer 1

transverse waves have oscillations perpendicular to the direction of wave travel whereas longitudinal waves have oscillations in the same direction as the direction of travel of the wave

Question 2

1. b) figure 1 shows a ripple tank, used to study the behaviour of water waves.

water waves are produced in the tank the shadow of the waves is projected onto the screen below the tank. the waves appear to move in the direction of the arrow.

i) describe how to determine the frequency of the waves

Answer 2

measure time taken for waves to pass a fixed point and use equation:
frequency = number of waves / time taken

Question 3

1. b) figure 1 shows a ripple tank, used to study the behaviour of water waves.

water waves are produced in the tank the shadow of the waves is projected onto the screen below the tank. the waves appear to move in the direction of the arrow.

ii) the screen is 80cm long, what is the approximate wavelength of the waves as seen on the screen? (MC)

Answer 3

A - 4cm

Question 4

1. b) figure 1 shows a ripple tank, used to study the behaviour of water waves.

water waves are produced in the tank the shadow of the waves is projected onto the screen below the tank. the waves appear to move in the direction of the arrow.

iii) a student uses the image to estimate the speed of the water wave as 75cm/s. which of these is a reason why the estimate is not correct? (MC)

Answer 4

D - the wave seen on the screen is magnified

Question 5

2. a) scientists no longer accept the geocentric model of the universe but it was the accepted theory for hundreds of years.

explain why the evidence available at the time supported the geocentric model

Answer 5

at the time there was only naked eye evidence which indicated Sun/Moon/planets appear to move across the sky in the same direction and motion each day

Question 6

2. b) the big bang theory and the steady state theory are two theories about the origin of the universe.

the discovery of CMB led scientists to accept only one of the theories.

explain why red shift supports both theories but CMB only supports one of them

Answer 6

both theories predict an expanding universe and the big bang theory also predicts the universe had a beginning. the redshift theory indicates that the universe is expanding so supports both theories whereas CMB also indicates that the universe has a beginning so supports the big bang theory

Question 7

2. c) i) a star with a mass very much larger than the sun … (MC)

Answer 7

B - has a longer main sequence than the sun and ends as a black hole

Question 8

2. c) ii) which row has two correct statements about black holes? (MC)

Answer 8

B - allows nothing to escape (gravity of black hole) , a very large star collapses (black hole formed when)

Question 9

3. a) Figure 2 shows some lines in the absorption spectra from four different galaxies (A, B, C, D) and from a laboratory source.

all spectra are aligned and to the same scale.

i) explain, using figure 2, which galaxy is furthest away from us

Answer 9

galaxy C has the biggest red shift, therefore having the greatest speed. since the galaxy with the greatest speed will be furthest away, then galaxy C is at the furthest distance

Question 10

3. a) Figure 2 shows some lines in the absorption spectra from four different galaxies (A, B, C, D) and from a laboratory source.

all spectra are aligned and to the same scale.

ii) in figure 2, the reference wavelength, is shown at 390 nm. estimate the change in the reference wavelength, for the light from galaxy D

Answer 10

20 nm

Question 11

3. a) Figure 2 shows some lines in the absorption spectra from four different galaxies (A, B, C, D) and from a laboratory source.

all spectra are aligned and to the same scale.

iii) calculate the speed, v, of galaxy D. use the equation:

v = c x wavelength / wavelength 0

Answer 11

v= (3 x 10^8) x (20 x 10^-9) / (390 x 10^-9)

= 15,400,000

Question 12

3. b) figure 3 shows a photograph of galaxy D. the photograph was taken by a student at his home.

state two ways that the student can improve the observational techniques so that the quality of the image is improved

Answer 12

1) better quality objective lens

2) move telescope to better viewing conditions (eg higher up a mountain, dark skies)

Question 13

4. figure 4 shows 2 students investigating their reaction times. student B supports his left hand on a desk. student A holds a ruler so that the bottom end of the ruler is between the finger and thumb of student B. when student A releases the ruler, student B catches the ruler as quickly as he can. the investigation is repeated with the right hand of student B.
   a) the students took five results for the left hand and five results for the right hand. figure 5 shows their results.
   i) calculate the average distance dropped for the right hand. give to 2 s.f

Answer 13

12.5 + 16.1 + 19.4 + 18.6 + 20.2 / 5

= 18.36

= 18

Question 14

4. figure 4 shows 2 students investigating their reaction times. student B supports his left hand on a desk. student A holds a ruler so that the bottom end of the ruler is between the finger and thumb of student B. when student A releases the ruler, student B catches the ruler as quickly as he can. the investigation is repeated with the right hand of student B.
   a) the students took five results for the left hand and five results for the right hand. figure 5 shows their results.
   ii) calculate the average for the left hand. use the equation:

time^2 = distance / 500

Answer 14

t = square root of distance / 500

= 14/500 = square root of 0.028

= 0.1683

= 0.17

Question 15

4. figure 4 shows 2 students investigating their reaction times. student B supports his left hand on a desk. student A holds a ruler so that the bottom end of the ruler is between the finger and thumb of student B. when student A releases the ruler, student B catches the ruler as quickly as he can. the investigation is repeated with the right hand of student B.
   b) explain whether any of the readings are anomalous

Answer 15

25.5 is an anomalous result because it is much further away from the mean than the other results

Question 16

4. figure 4 shows 2 students investigating their reaction times. student B supports his left hand on a desk. student A holds a ruler so that the bottom end of the ruler is between the finger and thumb of student B. when student A releases the ruler, student B catches the ruler as quickly as he can. the investigation is repeated with the right hand of student B.
   c) give two ways that the students can improve the quality of their data other than ignoring anomalous results

Answer 16

1) take more readings

2) a third students should also measure their reaction time

Question 17

4. figure 4 shows 2 students investigating their reaction times. student B supports his left hand on a desk. student A holds a ruler so that the bottom end of the ruler is between the finger and thumb of student B. when student A releases the ruler, student B catches the ruler as quickly as he can. the investigation is repeated with the right hand of student B.
   d) describe how the students could develop their investigation to investigate how reaction time changes with another variable

Answer 17

using a larger group of students and measuring how their reaction time varies with age and height

Question 18

5. a) a car accelerates at a constant rate of 1.83m/s^2 along a flat straight road. the force acting on the car is 1870 kN. calculate the mass of the car to 3 s.f

Answer 18

m = f / a

m = 1870 / 1.83

= 1020

Question 19

5. b) the car accelerates from rest for 16s. calculate the speed of the car after 16s

Answer 19

v = u + at

v = 0 + 1.83 x 16

= 29.3

Question 20

5. c) the car starts on another journey. figure 6 shows the graph of the cars movement.

show that the distance travelled when the car is moving at a constant speed is greater than the distance travelled when the car is slowing down.

Answer 20

area under AB = 240m

area under CD = 135m

distance travelled at constant speed = 240m is greater than distance travelled when slowing down = 135m

Question 21

6. figure 7 shows the nuclei of four atoms (uranium 234/235, plutonium 238, americium 238)
   a) which two nuclei have the same number of neutrons? (MC)

Answer 21

B - uranium 235 and americium 238

Question 22

6. figure 7 shows the nuclei of four atoms (uranium 234/235, plutonium 238, americium 238)
   b) i) state what is meant by the term half life

Answer 22

the time taken for the activity of a radioactive nuclide to halve

Question 23

6. figure 7 shows the nuclei of four atoms (uranium 234/235, plutonium 238, americium 238)

b) ii) plutonium-238 is used in spacecraft to provide heat to power generators. one of these generators contains 925g of plutonium-238 when it is manufactured. one gram of plutonium-238 has a power density of 0.54 w/g. plutonium-238 has a half-life of 87.7 years.
calculate the average energy released per second by the generator after 263 years.

Answer 23

263 / 87.7 = 3

3 half lives = 1/2 x 1/2 x 1/2 = 1/8

mass of pu-238 after 3 half lives = 925 / 8 = 115.625g

115.625 x 0.54 = 62.4

=62.4

Question 24

6. figure 7 shows the nuclei of four atoms (uranium 234/235, plutonium 238, americium 238)
   c) the nucleus of americium-238 can absorb an electron. when this happens, one of the protons in the nucleus becomes a neutron, as shown in figure 8.

1 0 1
p + e —> n
1 -1 0

i) describe how absorbing an electron affects the proton number and the nucleon number of a nucleus

Answer 24

atomic number decreases by one, mass number remains unchanged

Question 25

6. figure 7 shows the nuclei of four atoms (uranium 234/235, plutonium 238, americium 238)
   c) the nucleus of americium-238 can absorb an electron. when this happens, one of the protons in the nucleus becomes a neutron, as shown in figure 8.

1 0 1
p + e —> n
1 -1 0

ii) deduce which nucleus is formed when americium-238 absorbs an electron (MC)

Answer 25

C - plutonium-238

Question 26

7. a) students investigates how the average speed of the trolley varies with starting height. figure 9 shows the trolley and runway.

describe how the student can determine the average speed of the trolley

Answer 26

use suitable timing equipment to measure time between two positions (stopwatch and lightgates) . also measure the runway of suitable distance with a metre rule. also measure vertical height to starting position.

Question 27

7. b) students investigates how the average speed of the trolley varies with starting height. figure 9 shows the trolley and runway.

figure 10 shows his results

i) the trolley has a mass of 650g. calculate the average kinetic energy of the trolley which had a starting height of 0.075m

Answer 27

0.5 x 0.65 x (0.61)^2

= 0.12J

Question 28

7. b) students investigates how the average speed of the trolley varies with starting height. figure 9 shows the trolley and runway.
   ii) determine the gradient of the graph when the height is 0.1m

Answer 28

(tangent to graph at h = 0.1)

= 3.5

Question 29

7. b) students investigates how the average speed of the trolley varies with starting height. figure 9 shows the trolley and runway.
   iii) describe how the speed of the trolley varies with the changes in height made by the student between 0.04 and 0.12m

Answer 29

for each change in height, as the height increases the speed of the trolley increases. the greatest change in speed is between the change in height from 0.04m to 0.09m

Question 30

7. c) the student wants to change his experiment to investigate how different surfaces of the runway affect the speed of the trolley down the slope.

devise an experiment that would allow him to investigate the effect of different surfaces on the average speed of the trolley

Answer 30

use a constant height, slope and starting points and the same length of surface - use at least 3 different surfaces. then calculate the average speed for each surface and repeats

Question 31

8. a) all objects emit electromagnetic radiation. the intensity and wavelength of the emitted radiation vary with the temperature of the object. figure 13 shows this variation for a filament lamp at two different temperatures. the visible region of the electromagnetic spectrum is also shown.

explain why a filament lamp appears brighter and less red as temperature increases

Answer 31

intensity of radiation increases with temperature. the distribution of the emitted wavelengths of radiation is affected by temperature. at low temperatures the intensity of radiation emitted is low and the range of emitted wavelengths are high so the lamp appears dull red. at high temperatures intensity of radiation is greater and range of emitted wavelengths is low so lamp appears brighter and less red

Question 32

8. a) all objects emit electromagnetic radiation. the intensity ad wavelength of the emitted radiation vary with the temperature of the object. figure 13 shows this variation for a filament lamp at two different temperatures. the visible region of the electromagnetic spectrum is also shown.
   ii) count rate = k / d^2

find count rate when placed 1.3m from source of gamma radiation when count rate was 85 000 at 0.70m

Answer 32

k = 85000 x 0.70^2

count rate = 85000 x 0.70^2 / 1.3^2

= 25000

Question 33

8. b) sulfates and black soot are particles formed by industrial processes. some of these particles are found in the atmosphere over the arctic ocean. the sulfates stay in the atmosphere and reflect sunlight. the black soot falls onto the arctic ice.

discuss how a reduction in these industrial is likely to affect the temperature of the atmosphere

Answer 33

the soot could make the ice black, and black ice will absorb more infra red radiation than white ice and black ice might cause an increase in temperature because absorption of infra red radiation causes an increase in temperature.
reduction in soot might reduce warming because the ice will be more white. sulfates are good at reflecting infra red radiation which means less heat is absorbed. sulfates scatter the IR and this reduces the amount of IR radiation falling on earth, causing a decrease in the temperature, and increase warming on earth.

Question 34

9. a) explain what happens to the wavelength of light when it passes from air into glass

Answer 34

the wavelength decreases because wavelength is the ratio of wave velocity to frequency and the wave velocity reduces at the boundary but the frequency remains the same

Question 35

9. b) figure 13 shows a beam of red light approaching one side of a rectangular glass block. the beam of light will pass through the block and leave through the opposite side. AB is a wavefront

discuss the path of the wavefront AB as it enters and leaves the glass block

Answer 35

point A reaches the glass before point B. A moves into the glass block and slows down because light travels slower in glass than air but B is still in the air so travelling faster than A this causes part of the wavefront to refract. by the time B reaches the block it will have travelled further than A therefore the whole wavefront refracts towards the normal. at the other face, A exits first so the process is reversed. the wavefront changes direction again so it is parallel to its original direction and refracts away from the normal

Question 36

9. c) the distance between the earth and the sun is 1.50 x 10^11.
   light takes 500s to travel from the sun to the earth. the wavelength of red light is 670 nm.

calculate the frequency of red light, using only the data provided

Answer 36

v = s / t

v = 1.5 x 10^11 / 500

= f x 670 x 10^-9

f = (1.50 x 10^11) / 500 x (670 x 10^-9)

= 4.5 x 10^14

Question 37

10. in a nuclear reactor, a chain reaction is produced and controlled
    a) i) uranium-235 is the isotope used in many nuclear reactors.

explain how the fission of uranium-235 can lead to a chain reaction

Answer 37

fission results in 2 or 3 neutrons to be released and one or more of these released neutrons are absorbed by other nuclei which can cause further fission of U nuclei and release further neutrons that can be absorbed, causing a chain reaction

Question 38

10. in a nuclear reactor, a chain reaction is produced and controlled

ii) nuclei of beryllium-9 do not absorb neutrons. instead, nuclei of beryllium-9 absorb alpha particles and emit neutrons.
give a reason why a chain reaction can result from the emission of neutrons by uranium nuclei but not by beryllium nuclei

Answer 38

to get a chain reaction, the particle that impacts the nucleus must be the same as the one released

Question 39

10. in a nuclear reactor, a chain reaction is produced and controlled
    b) explain what happens inside a nuclear reactor if neutron speeds aren’t controlled

Answer 39

reaction will slow down because there are fewer fissions, because fission is more likely with slow neutrons

Question 40

10. c) describe how the energy released in the chain reaction in a nuclear reactor is used to drive a turbine in a nuclear power station

Answer 40

the reactor is surrounded by a coolant. the thermal energy released from the chain reaction heats the coolant. the hot coolant is used to generate steam which is used to drive the turbine