National 5

Physics

Waves and Radiation

Homework

Open Ended Questions

Assignment Practice

Created G.Gibb Denny High School

These homeworks cover

Knowledge and understanding

Problem Solving skills

Open ended questions

Assignment practice questions

o All the above are essential parts of the National 5 Physics course. Completing these

homeworks allow distributed practice over the session which will lead to an

improved final grade.

o You may start these homeworks at any time and spread the work over several

evenings. This is good practice.

o Most of these homeworks are too large to be completed in a single sitting. Rushing

to do these homeworks the evening before they are due will not allow sufficient time

to complete them. Poor understanding will result.

o All working should be shown.

o Answers must have correct units.

o These homeworks will normally be expected to be handed in one week after

completion of the class work on that key area.

When doing open ended questions, you should:

1. read the question, taking care not to skim-read

2. reread the question

3. try to understand/define the problem situation and what is asked

4. visualise the situation

5. draw a diagram and include any relevant information such as speeds, velocities,

forces, vector directions, etc.

6. determine and write down:

(a) any relevant physics principles, e.g. conservation of energy

(b) the area/topic of physics involved in the problem, e.g. electricity

(c) the relationship relevant to variables in the problem

7. use knowledge of familiar quantities, such as body mass, body height, length of

running track, to create estimated values as required

8. with the information noted previously, solve the problem, remembering that partial

marks can be awarded

9. reread the response to see if it makes sense and answers the question

Wave parameters and Behaviours

Knowledge, Understanding and Problem Solving Questions

Q1. A wave does not transport material over any great distance. What does a wave

transfer?

Q2 Define the following, giving symbols and units where appropriate.

Amplitude

Wavelength

Frequency

Null position

Crest

Trough

Wave speed

Q3. Describe in terms of the motion of particles and the motion of the wave

a. a transverse wave

b. a longitudinal wave.

Q4. Draw a table with appropriate headings showing which of these waves are

transverse waves and which are longitudinal waves

Sound waves, seismic P waves, seismic S waves, microwaves, x-rays, water waves,

gamma rays.

Q5. ‘A-B’ represents one wavelength in the diagram below.

State two other pairs of letters which represent one wavelength.

Q6. How many waves are shown in each of the diagrams below?

A B

C D E

F G

A B

C D

Q7. Complete the following table for the quantities used in the relationship 𝑣 = 𝑓𝜆.

Quantity Symbol Unit Unit abbreviation

Wave speed v

Frequency

λ

Q8. The diagram shown below shows a wave of frequency 4.0Hz.

Find

a. The wavelength of the wave.

b. The period of the wave.

c. The amplitude of the wave.

d. The wave speed.

15m

3.0m

Q9. A transmitter transmits both long wave radio waves and a shorter wave FM radio

waves.

a. If you are driving a van on the opposite side of the mountain to the transmitter state

which of the broadcasts you are most likely to receive?

b. Explain you answer to part a.

Q10. Bottlenose dolphins produce sounds in the frequency range 200 Hz – 150 kHz.

Bottlenose dolphins use ultrasounds for echolocation which is the location of objects

by using reflected sound. .

a. A dolphin is out hunting and sends out a sound pulse when it is 10m from a fish. The

speed of sound in seawater is 1500ms-1.

Calculate the time taken for this pulse to return to the dolphin.

b. A fish swims away rapidly. State how the time now taken for the reflected pulse to

return compares to the time in part a.

Q11. For the table below.

a. Write the correct units into the headings

b. Use 𝑣 = 𝑓𝜆 to complete the blanks in the table.

Speed ( ) frequency ( ) Wavelength ( )

4.0 1.2

3.0 × 108 5.0 × 1014

3.0 × 108 0.5

Open Ended Question

Q12. From section 1.1 in your Waves and Radiation Notes the following is

written about waves

Waves move energy from one place to another. They consist

of an oscillation in a material or field without the

transfer of the material itself.

By considering the above statement and your

knowledge of physics comment on how a

surfer can move forward by riding a wave.

Assignment Practice Question

Q13. In an experiment to find the speed of sound in steel, the time it took for sound to

travel through steel bars of various length was recorded.

Length (m) Time (× 10−6s) Mean Time (× 10−6s)

0.5 82, 82, 81

1.0 164, 155, 166

1.5 200, 245, 251

2.0 300, 340, 326

a. Calculate the mean time for sound to travel the lengths of steel bar.

b. On the graph paper on the next page plot a graph of mean time against length.

c. Use the data to find the speed of sound in steel.

d. Use the internet or other source to find the accepted value of the speed of sound in

steel. Record the URL of your source of information if you used the internet. Record

where you obtained the information if you used another source.

e. Compare the speed of sound in steel from the experiment with that obtained from

your source in part d.

f. Suggest one way in which this experiment could be improved.

Scatter Graph Checklist

Each scatter graph must contain

Axes with labels and units

A horizontal axis with an evenly spaced scale

A vertical axis with an evenly spaced scale

Correctly plotted points

A best fit line.

Electromagnetic Spectrum and Light

Q1a. The diagram below shows part of the electromagnetic spectrum.

Which line in the table shows the correct types of electromagnetic wave for regions

P & Q?

b. Which of the electromagnetic wave bands has

(i) The longest wavelength?

(ii) The highest frequency?

(iii) The highest energy?

Q2. In a long distance phone call routed through a geostationary satellite there is a delay

between speaker talking and the listener hearing the sound. This is due to the time

taken for the microwave signal to be sent to and return from the satellite.

a. Use the data below to calculate this time delay.

Height of the geostationary satellite = 36,000km

Speed of Microwaves = 3.0 × 108ms−1

b. Another geostationary satellite uses radio waves rather than microwaves. Comment

on how this would affect the time delay. Give a reason for your answer.

Radio P Infrared Visible Q X-rays Gamma

rays

Region P Region Q

A microwaves infrared

B infrared ultraviolet

C microwaves infrared

D infrared microwaves

E microwaves ultraviolet

Q3. Complete the table below giving a detector and an application of each band in the

electromagnetic spectrum.

E-M Spectrum Band Detector Application

Radio

Microwave

Infrared

Visible

Ultra-violet

X-ray

Gamma

Q4. What is meant by the term ‘refraction’?

Q5. Label the diagram with the following: Incident ray, Refracted ray, Angle of incidence,

Angle of refraction, Normal.

Q6. Which of these diagrams shows what

happens when a ray of light:

a. travels from air in to glass.

b. travels from glass in to air.

A B

C D

Open Ended Question

Q7. After the chateau explodes, the evil villain in a Bond movie sees 007 swimming away under

water. He fires his gun at him. Using your knowledge of physics comment, with the aid of a

labelled diagram(s), on the likelihood of the bullet hitting 007.

Assignment Practice Question

Q8. An experiment to investigate the relationship between angle of incidence and angle of refraction when light is moving from air in to glass is performed. The following data is obtained. Plot this data on a scatter graph.

Angle of Incidence

(Degree)

Angle of Refraction

(Degree)

0 0

10 6

20 13

30 19

40 25

50 31

60 35

Nuclear Radiation

Q1. A radioactivity kit includes three radioactive sources each made up as shown.

Information about these sources is given in the table below.

Radiation Emitted Radioactive Element

Source 1 Alpha Americium 241

Source 2 Beta Strontium 90

Source 3 Gamma + Beta Cobalt 60

a. Unfortunately the labels have come off the sources. You are given a GM counter a

sheet of paper, a thick sheet of aluminium and a thick sheet of lead. Describe how

you would use this equipment find which source is which.

b. The half-life of Cobalt 60 is 5.3years. The initial activity of a schools Cobalt 60 source

is 8.0kBq. If the school disposes of the source when it reached an activity of 500Bq

how many useful years would the school get from the source?

Q2. A radioactive tracer is a gamma emitting chemical compound that can be injected in

to a patient in hospital. Describe how this can be useful in diagnosis of medical

problems.

Mounting Peg

Lead Case

Radioactive source inside

Thin “window” through which radiation is

emitted.

Q3. Gamma rays can also be used to treat cancer in a method known as radiotherapy.

Describe how a patient can have a cancer treated in this way, and how damage to

surrounding healthy tissue is minimised.

Q4. An experiment is carried out to determine the half-life of a radioactive gas. A Geiger-

Müller (GM) tube and counter are used to measure the background radiation. The

apparatus shown is then used to measure the count rate with the radioactive gas in

the gas cell. The readings are corrected for background radiation.

Time (minutes) Corrected count rate (counts per second)

0 168

2 120

4 84

6 60

8 42

10 30

12 21

a. State what is meant by the activity of a radioactive source.

b. What is “background radiation”.

Counter

Radioactive

Gas Cell

Timer GM Tube

c. Use the information in the table to predict the corrected count rate at 9 minutes.

d. Use the information in the table above to draw a line graph of the count rate of the

source against time.

e. Use the graph to find the half-life of the source.

Q5. The average person in the UK receives annual doses of radiation given in the table

below.

Background Source Equivalent Dose / mSv

Radon Gas (from rocks) 1.25

Buildings 0.35

Medical 0.35

Food & Drink 0.30

Cosmic Rays 0.25

Nuclear Power & Weapons 0.0075

Select from the table the sources which have the greatest and least contribution to a

person’s radiation exposure.

Q6a. Name the nuclear process shown in the diagram below.

b. Other than Barium, Krypton and neutrons what else is produced in this process.

Neutron

Uranium 235

Nucleus

Krypton 92

Nucleus

Barium

141

Neutrons

Uranium 235

Nucleus

Q7. The effective dose equivalent limit for exposure to radiation of a worker is 200mSv

per year.

In one area of the plant a worker gets and absorbed doses of

1.0mGy of gamma radiation

200μGy of slow neutrons

80μGy of alpha particles

each hour when working in this area.

a. Calculate the equivalent dose for each of the three types of radiation.

You will need to use the data sheet at the end of your notes.

b. Find the effective equivalent dose

c. The recommended effective dose equivalent limit must not be exceeded.

Calculate the maximum number of working hours in one year permitted

in this area.

Open Ended Question

Q8. While thinking about nuclear radiation, its uses and effects, the thinker has the

thoughts shown below. Use your knowledge of physics to comment on these

thoughts.

Radiation does us no

harm. We are

exposed to it all the

time.

Nuclear energy is

environmentally friendly

as it does not emit carbon

dioxide.

Nuclear radiation is used

to cure cancer, so nuclear

radiation is good for you.

Assignment Practice Question

Q9a. An experiment to find the half-life of a protactinium-234 radiation source found the

following data.

Time (s) Corrected Count rate (Counts per second)

0 320

20 263

40 215

60 177

80 145

100 119

120 98

140 80

a. On the graph paper on the next page draw a graph of corrected count rate against

time.

b. Using the graph find the half-life of protactinium-234.

c. Using the internet or other source find the half-life of protactinium-234. Record the

URL of your source of information if you used the internet. Record where you

obtained the information if you used another source.

d. Compare the half-life from the experiment with the half-life from the source in part

c.

Scatter Graph Checklist

Each scatter graph must contain

Axes with labels and units

A horizontal axis with an evenly spaced scale

A vertical axis with an evenly spaced scale

Correctly plotted points

A best fit line.