AS 7 Waves PDF

When the source and observer is stationary When source moves towards to the oberver Source is moving towards with higher speed The moving speed is higher than source speed The source is moving away from Source is moving away with source speed Doppler effect Doppler effect Observed frequen...

When the source and observer is stationary When source moves towards to the oberver Source is moving towards with higher speed The moving speed is higher than source speed The source is moving away from Source is moving away with source speed Doppler effect Doppler effect Observed frequency is different to source frequency when source moves relative to observer. Move towards Observed frequency is higher. Pitch is higher. Move towards blue in the electromagnetic spectrum. Move away Pitch is lower. Move towards red in the electromagnetic spectrum. Equation Away 𝑣 𝑜𝑏𝑠𝑒𝑟𝑣𝑒𝑑 𝑤𝑎𝑣𝑒𝑙𝑒𝑛𝑔𝑡ℎ 𝜆0 = 𝑓𝑠 𝑣 𝑣𝑓𝑠 𝑜𝑏𝑠𝑒𝑟𝑣𝑒𝑑 𝑓𝑟𝑒𝑞𝑢𝑒𝑛𝑐𝑦 𝑓0 = = 𝜆0 𝑣 + 𝑣𝑠 𝑣 + 𝑣𝑠 𝑜𝑏𝑠𝑒𝑟𝑣𝑒𝑑 𝑤𝑎𝑣𝑒𝑙𝑒𝑛𝑔𝑡ℎ 𝜆0 = 𝑓𝑠 Equation Towards 𝑣 𝑜𝑏𝑠𝑒𝑟𝑣𝑒𝑑 𝑤𝑎𝑣𝑒𝑙𝑒𝑛𝑔𝑡ℎ 𝜆0 = 𝑓𝑠 𝑣 𝑣𝑓𝑠 𝑜𝑏𝑠𝑒𝑟𝑣𝑒𝑑 𝑓𝑟𝑒𝑞𝑢𝑒𝑛𝑐𝑦 𝑓0 = = 𝜆0 𝑣 − 𝑣𝑠 𝑣 − 𝑣𝑠 𝑜𝑏𝑠𝑒𝑟𝑣𝑒𝑑 𝑤𝑎𝑣𝑒𝑙𝑒𝑛𝑔𝑡ℎ 𝜆0 = 𝑓𝑠 Doppler effect equation 𝑣 𝑣𝑓𝑠 𝑓0 = = 𝜆0 𝑣±𝑣𝑠 𝑓0 is observed frequency v is wave speed 𝑓𝑠 is source emitting frequency 𝑣𝑠 is relative speed between source and observer +: moving away relatively; observed frequency decreases -: moving towards relatively; observed frequency increases D C