Formative Practice 5.5 – Physics Form 4 Chapter 5


Question 1:
Complete the following diagrams by drawing the patterns of diffracted waves.



Answer:
(a)

(b)

(c)

(d)


Question 2:
Figure 5.54 shows a plan of the living room and bedroom. A child lying on the bed cannot see the television in the living room but can still hear the sound from the television.

(a) By drawing wavefronts, explain how the phenomenon of diffraction enables the child to hear sound from the television.

(b) State another phenomenon which causes sound to propagate from the television to the child.

Answer:
(a)


The wavelength of sound waves is long. The sound of the television can spread and bend around a space or an obstacle due to diffraction of sound. As a results, the child at the bedroom can hear the sound of the television.

(b)
Reflection of sound waves from the wall.