We've updated our privacy policy. Click here to review the details. Tap here to review the details.

Successfully reported this slideshow.

Your SlideShare is downloading.
×

Activate your 30 day free trial to unlock unlimited reading.

Activate your 30 day free trial to continue reading.

Top clipped slide

1 of 16
Ad

Download to read offline

The Doppler Effect

The Doppler Effect

- 1. The Doppler Effect By Brigette Wee
- 2. The Doppler Effect What is it? It is the shift in frequency of a wave due to the relative motion of the source of the sound with respect to the receiver of the sound If there is relative motion between the source and receiver of sound, the frequency at the receiver is different from frequency that is transmitted if moving towards each other: received frequency is higher if moving away from each other: received frequency is lower It can be expressed as a single equation: fr: frequency of the receiver fs: frequency of source vr:: speed of receiver Vs: speed of source V: speed of wave
- 3. How do we use the equation? When do we use ± in the numerator? If the receiver is moving toward the source, the received frequency is higher Thus, we use the top sign in the numerator, which is + If the receiver is moving away from the source, the received frequency is smaller Thus, we use the bottom sign in the numerator, which is - When do we use in the denominator? If the source is moving toward the receiver, the received frequency is higher Thus, we use the top sign in the denominator, which is – If the source is moving away from the receiver, the received frequency is smaller Thus, we use the bottom sign in the denominator, which is +
- 4. Scenario 1: Moving Source, Stationary Receiver Stationary receiver means vr:= 0 Thus, we use this equation if the source is moving towards a stationary receiver: Note: if the source is moving away from the stationary receiver, a plus sign would be on the denominator of the equation above If source is moving to right, the wave front to the right of source are closer (as shown in the figure) meaning there are more waves per second (higher frequency) thus, the receiver to the right will detect more waves Note: same rational as above if the source is moving to the left
- 5. Scenario 2: Moving Receiver, Stationary Source Stationary source means Vs= 0 Thus we this equation if the receiver is moving towards the source: • Note: if the receiver is moving away from the source, there would be a – sign on the numerator
- 6. Scenario 3: Moving Receiver, Moving Source In this case, we can also use the equation: The signs on the denominator and numerator will depend on whether the receiver and source are moving towards or away from each other Please refer to slide 3 for reference.
- 7. Scenario : A female whale (travelling at 15km/hr) and a male whale (travelling at 25km/hr) are trying to move towards each other in order to mate. However, they must first send out sound waves to locate each other. The male whale sends out a sound wave travelling at 6000km/hr and a frequency of 1000Hz Application of the Doppler Effect in Whale Mating
- 8. 25 km/hr 15km/hr
- 9. What is the frequency detected by the female whale? Question 1
- 10. First make an educated guess as to whether the received frequency has a higher/lower magnitude Since they are moving towards each other, the received frequency will be higher Solution: Step 1
- 11. First determine what equation is appropriate in the given scenario: They are moving towards each other They are both moving So we use this equation: *Since they are moving towards each other: *Note the signs Use a + in the numerator Use a – in the denominator REMEMBER: FIGURING OUT THE SIGN IS AN IMPORTANT STEP (PLEASE REFER TO SLIDE 3 FOR A SUMMARY) Solution: step 2
- 12. Assign the variables: fr: frequency of female whale (solve for this) fs: frequency of male whale (1000Hz) vr:: speed of female whale (15km/hr) vs: speed of male whale (25km/hr) v: speed of sound (6000km/hr) Solution: step 3
- 13. Plug in your numbers and you should get… Note that km/hr does not need to be converted to m/s as it cancels out in the fraction. Solution: Final answer
- 14. YESS!! The received frequency (10006Hz) is higher than 1000Hz Does our final answer agree with our educated guess in step 1?
- 15. THANK YOU
- 16. Physics for Scientist and Engineers An Interactive Approach by Hawkes, Iqbal, Mansour Milner-Bolotin, Williams Work cited

No public clipboards found for this slide

You just clipped your first slide!

Clipping is a handy way to collect important slides you want to go back to later. Now customize the name of a clipboard to store your clips.Hate ads?

Enjoy access to millions of presentations, documents, ebooks, audiobooks, magazines, and more **ad-free.**

The SlideShare family just got bigger. Enjoy access to millions of ebooks, audiobooks, magazines, and more from Scribd.

Cancel anytime.Total views

2,077

On SlideShare

0

From Embeds

0

Number of Embeds

1,296

Unlimited Reading

Learn faster and smarter from top experts

Unlimited Downloading

Download to take your learnings offline and on the go

You also get free access to Scribd!

Instant access to millions of ebooks, audiobooks, magazines, podcasts and more.

Read and listen offline with any device.

Free access to premium services like Tuneln, Mubi and more.

We’ve updated our privacy policy so that we are compliant with changing global privacy regulations and to provide you with insight into the limited ways in which we use your data.

You can read the details below. By accepting, you agree to the updated privacy policy.

Thank you!

We've encountered a problem, please try again.