1. Question 1 – 5 marks Law of Reflection:
Angle of Incidence = Angle of Reflection.
Angle of reflection
Normal line
Angle of incidence

2. Question 2 – 6 marks
Angle of refraction i
Normal Line

3. Question 3 table – 6 marks Part of Spectrum Gamma X-ray UV Used for
Cancer treatment
Scanning bones
Sterilising
Visible
Infra Red
Microwave
Radio
Seeing
Thermal imaging
Cooking/
communications

4. Question 3 passage – 5 marks
All electromagnetic waves travel at the same speed/speed of light which is about km/s in a vacuum. All electromagnetic waves can carry energy from one place to another. All electromagnetic waves can be reflected or refracted. The high frequency end of the spectrum is gamma waves and the low frequency end is radio waves.

5. Question 4 – 8 marks 3 primary colours – Red, blue, green (1)
Cyan made from – Green and Blue (1)
3 primary colours mixed evenly - White (1)
Blue t-shirt viewed through red filter – Black, Red filter only transmits red light, t-shirt reflects only blue therefore no red to transmit. (2)
Yellow T-shirt viewed through green filter – Green, T-shirt reflects Yellow light (Green & Red). Green filter only transmits green light, so t-shirt looks green. (3)

6. Question 5
Sound can travel through solids, gases and liquids but not a vacuum. In sound waves, the tiny particles are pushed together and pulled further apart. This type of wave is called longitudinal / compression. The frequency of a sound is measured in Hertz or Hz for short. A high pitched note has a high frequency. The range of human hearing is approximately from 20 up to Hz, although older people tend to lose the upper range or their hearing.

7. Question 6 – 4 marks Amplitude = 1.1cm Wavelength = 2.9cm
Louder wave with higher pitch:
Waves have larger amplitude and are closer together (higher frequency)

8. Question - 7 3.85s 3.0 s 480 x 2 = 960 speed = distance/time = 960/3
= 320 m/s