A wave travelling through a material has a frequency of 50 Hz and a wavelength of 0.40 m. How long does it take the wave to travel 100 m through this material?

Answer:

7) E

Using c = f λ,

Speed of wave in material = 50 x 0.4 = 20 m/s

Time = Distance ÷ Speed = 100 ÷ 20 = 5 s