Calculating Car Speed from Horn Frequency

AI Thread Summary
To calculate the speed of a car approaching with a horn frequency of 450 Hz, while the observed frequency is 503.7 Hz, the Doppler effect must be applied. The speed of sound is given as 1100 ft/sec. Relevant equations include those relating frequency, wavelength, and velocity of sound waves, as well as specific Doppler effect formulas. The discussion highlights the need for a clearer understanding of these equations to solve the problem effectively. The user seeks guidance on how to begin the calculations.
Moroni
Messages
11
Reaction score
0

Homework Statement



A car approaches blowing its horn. The observed frequency is 503.7 Hz Assume that the speed of sound is 1100 ft/sec. the car's horn has a frequency of 450 Hz How fast is the car traveling.




Homework Equations


?



The Attempt at a Solution



I can't even figure out how to start. Sorry for my ignorance.
 
Physics news on Phys.org
Thread moved from Advanced to Intro Physics.

Try again to list the relevant equations. What equation relates the frequency, wavelength and velocity of sould waves? What equations are you shown in your text or other learning materials for the Doppler effect? What does the wikipedia.org page say about the Doppler effect?
 
cb694f347a7ff458020624f46c56faf8.png


Is this it?

Thank You!
 

Thread 'Errors and significant figures'

I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
View full post »
Thread 'A cylinder connected to a hanging mass'

Thread 'A cylinder connected to a hanging mass'

Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
View full post »

Similar threads

Travelling towards a Canyon Wall: Calculating Beat Frequency
Replies
3
Views
2K
Calculating frequencies with the Doppler Effect
Replies
1
Views
3K
JF -"Discover the Relationship Between Observed Frequencies: Car 1 and Car 2"
Replies
15
Views
4K
How Does the Doppler Effect Explain Frequency Changes in Moving Cars?
Replies
3
Views
8K
Graphs of Frequency for Car Moving in a Circle
Replies
24
Views
3K
Calculating Intensities of Out-of-Phase Sound Waves
Replies
1
Views
2K
How Fast Was the Car Moving in the Radar Speed Trap Experiment?
Replies
8
Views
2K
Stuck for 2hrs on this frequency question
Replies
3
Views
3K
Calculating Doppler Effect: Car Speed and Frequency Analysis
Replies
15
Views
10K
Help with question on motion: Avoiding a rear-end collision
Replies
6
Views
3K

Hot Threads

Recent Insights

Back
Top