Name: /20 marks Module 8: Developing Level (3 marks each) 4) Radio telescopes receive radiowaves from distant stars. If such a wave has a wavelength of 24 cm and travels at the speed of light (c = 3.00 x 108 m/s), what is the frequency? d= 24 cm = 0, 241 m Given : wavelength ( 7) = 24 cm V = 3x 108 mis speed ( v) = 3.80 x 108 mls f = y Required : frequency (f ) v = 3x 10 m/5 - 12. 5 x 10$ Hz 0. 24 m - 1.3 x 10 H2 The frequency is 1. 3 x 10" AL. 5) The speed and wavelength of coastal water waves are 4.0 m/s and 6.0 m respectively. When the waves enter a shallower region, the speed decreases to 1.7 m/s. What is the wavelength in the shallower region? Given : Speed of V , = V 2 VI V2 coastal water N , - 72= = ( 21 ) waves ( v 1 ) = 4. owls 2 2 12 = 4 6 = 2.53 14 wavelength of 2 2 = (1.7 m /s ) ( 6.om ) coastal water waves = 2.55 m = 2. 6m (4, omls ) ( x , ) = 6.0 m speed at shallow water waves ( V2 ) = The wavelength in the shallow water region is 2.6m. 1.7 mls Required : Wavelength of shallow water Module 8: Proficient Level (2 marks) waves ( 72 ) 6) A train whistle has a frequency of 900 Hz and is moving away from you at 32.0 m/s. Given that the speed of sound is 340 m/s, what is the apparent frequency you hear? F5: 900HZ Given: Source frequency (fs ) = Us = 32 m/5 900 HZ V = 340 m 15 Source velocity ( Vs) = 32. omls fs = ( w - u ) v wave velocity ( Vw ) = 340 mals (3 = 900 (# # 32 ] Required: Apparent frequency ( f . ) V = 815. 29 HZ