Doppler Effect PDF

DOPPLER EFFECT Quarter 2, Week 5 What is a Doppler Effect? is the apparent change in the frequency of sound caused by the motion of the sound source and/or the observer. Doppler Effect It's an important phenomenon that occurs in all types of waves: sound waves, light waves and...

DOPPLER EFFECT Quarter 2, Week 5 What is a Doppler Effect? is the apparent change in the frequency of sound caused by the motion of the sound source and/or the observer. Doppler Effect It's an important phenomenon that occurs in all types of waves: sound waves, light waves and even water waves. Scientists have used the Doppler effect to make some amazing discoveries. Let's learn a little more about this phenomenon, so we can see why it's so important. For example: You may have noticed that as a fast moving siren passes by you, the pitch of the siren abruptly drops in pitch. At first, the siren is coming towards you, when the pitch is higher. After passing you, the siren is going away from you and the pitch is lower. This is a manifestation of the Doppler effect. In talking about how an observer perceives waves, we have to be clear about the difference between actual and apparent frequencies. Actual frequency is just what it sounds like: it's the true frequency of a wave, irrespective of external factors. The position of an observer does not affect the actual frequency of a wave. Apparent frequency is the frequency perceived by an outside observer. It may or may not match the actual frequency. Keep in mind that the speed of the waves is not changing. The speed depends only on the medium, and the medium isn’t changing. The waves travel at the same speed, but the observed frequency depends on any relative motion between the observer and source. A QUESTION FOR A ANSWER What is a Doppler Effect? A) is the apparent change in the frequency of sound caused by the motion of the sound source and/or the observer B) describes the inaction in frequency of any kind of sound or light wave produced by a moving source with respect to an observer What is a Doppler Effect? A) is the apparent change in the frequency of sound caused by the motion of the sound source and/or the observer B) describes the inaction in frequency of any kind of sound or light wave produced by a moving source with respect to an observer Question 2 A) sound waves only The Doppler effect is B) light waves only applicable for C) both sound and light waves Question 2 A) sound waves only The Doppler effect is B) light waves only applicable for C) both sound and light waves DOPPLER EFFECT FORMULA Doppler Effect = observer frequency of sound Formula = speed of the sound waves = observer velocity = source velocity = actual frequency of sound waves Doppler Effect A bat is flying towards a stationary wall at a constant speed of 50m/s. The bat emits a sound of 125Hz towards the wall, which is then reflected back at the bat. If the speed of sound in air is 343m/s, what is the frequency of sound that the bat experiences? Doppler Effect Thank you for listening !