Answers

Question 1

Q1)how does L and T oscillate (2)

Answer 1

L- ossolates parallel to direction of travel of wave

T- ossolates perpendicular to direction of travel of wave

Question 2

1)b)i) what is the amplitude? (1)

Answer 2

40mV

Question 3

1)b)ii) work out frequency (2)

Answer 3

Period= 1.5ms, frequency + 1/period= 1/1.5&raquo_space;»=667Hz«

Question 4

1)B)iii) work out wavelength (1)

Answer 4

330/667 = 0.49m

Question 5

1)c) (2) is the period the same

Answer 5

Intensity is proportional to amplitude squared so Same period (idk)

Question 6

2)a)i) what is the principal of superposition (1)

Answer 6

When two or more waves overlap, the resultant displacement at a point is equal to the vector sum of the individual displacements.

Question 7

2)a)ii) what is coherent (1)

Answer 7

Constant phase difference

Question 8

2)b)1/2) path difference (2)

Answer 8

1= 1 lambda
2= 1.5 lambda

Question 9

2)c) if A increases what will happen (2)

Answer 9

Lambda and D are constant so if A is increased separation of max increase

Question 10

3)a)i) suvat question (1)

Answer 10

V=u+at so t= 6.3/9.81 = 0.642s

Question 11

3)c) air resistance question (2)

Answer 11

With air resistance; reaches lower max height; will reach max height before hits wall; same initial path

Question 12

4)c) (4) PD changes

Answer 12

ldr will decrease so total resistance in circuit is less so current increases. So PD across 1.2k will increase, so PD across DR must decrease (PDs add up to 6v)

Question 13

5)b)i) (1) why use putty

Answer 13

So that the current flows through All cross sectional area of the putty

Question 14

5)b)ii) (2) experiment

Answer 14

Use micrometer at different points and different orientations
Use a template with hole of correct diameter and extrude

Question 15

5)c)i) (1)

Answer 15

6.6

Question 16

5)c)ii) (1) percentage uncertainty

Answer 16

Percentage uncertainty in L= 0.001/0.049 X 100= 2%

So percentage uncertainty in L^2= 2 x 2.0= 4%

Question 17

5)d)i) graph (2)

Answer 17

Plot point and draw line of best fit (NOT through false origin)

Question 18

5)d)ii) work out gradient (2)

Answer 18

5.7 ish

Question 19

6)a) on the wire pag thing with Steve (6)

Answer 19

• Wear safety glasses in case wire whiplashes in eyes
• Place cushion (soft thing) under load so it doesn’t break anything when it breaks
• Measure average diameter of wire in serval places using micrometer
• calculate cross sectional area = pi x (d/2)^2
• hang load off wire
• add weights one at a time until breaks, record breaking mass
• breaking stress= mass x 9.81 / cross sectional area

Question 20

6)b) (2) glass and rubber

Answer 20

Glass= straight line - steep
Rubber= curves - lower line when unloaded

Question 21

Q7)a) (6) photo electric effect

Answer 21

• One photon is absorbed and may release one electron if frequency of light is above threshold frequency of metal then electrons are emitted.
• UV has a higher frequency than visible
• E=hf so UV have more energy
• if Energy of photons is bigger than the work function energy of metal electrons are emitted.
• UV has enough energy, visible doesn’t
• when electrons are emitted change on electroscope drops and leaf falls because they aren’t repelling eachother

Question 22

8)c) (2) light experiment

Answer 22

• Rings will be close together and brighter

- Higher PD= more energy= greater V= smaller wavelength