​Learning Objectives

i. Students can explain what is waves.

ii. Students can name the two types of waves and make comparisons between them.

iii. Students can state what is amplitude, period, frequency, wavelength and wave speed.

iv. Students can draw both displacement-time graph and displacement-distance graph and extract the information from the graphs.

v. Students can calculate wavelength, frequency and wave speed.

​What is wave?

How waves are produced?​

​

​Transverse wave vs Longitudinal wave

Amplitude, A = maximum displacement from still position​

Period, T = time taken for one complete oscillation

Frequency, f = number of complete oscillation in one second

Wavelength, λ = distance between two consecutive crest/trough

Wave speed, v = rate of distance travelled by waves​

​

f = 1/T​

f = 1 / 2 s = 0.5 s^-1

v = λ​f

v = (10 cm)(0.5 s^-1)

​v = 5 cm s^-1

​

​v = λf

λ = 10 cm, T = 2 s

v = λ​/T

v = 10 cm / 2 s

v = 5 cm s^-1​

​v = λ/T

​Formula for wave speed, v?

1 Hz = 1 s^-1​

​Do Activity 5.5

(page 180)​

​Do Activity 5.6

(page 181)​

​Solution for Question 5

(page 226)

(a) Amplitude, A = 15 cm = 0.15 m

​Period, T = 1/f = 1 / 5 s^-1 = 0.2 s

Wavelength, λ = 1.2 m ÷​ 2 = 0.6 m

​

(b) v = λ​f

v = (0.6 m)​(5 s^-1)

v = 3 m s^-1​