What is the Doppler Effect of a Car's Music at Different Positions?

AI Thread Summary
The Doppler Effect describes how the frequency of sound changes based on the observer's position relative to the source. For a car moving at 25 m/s with music playing at 1800 Hz, a person standing in front of the car would perceive the sound at approximately 1938.5 Hz. Conversely, a person standing behind the car would hear the music at around 1680 Hz. These calculations assume sound travels at 350 m/s. The differences in perceived frequency highlight the impact of motion on sound waves.
Intrusionv2
Messages
31
Reaction score
0

Homework Statement


A car is driving down the road at 25m/s. Inside the car, the radio is blaring music at 1800Hz. How would it sound to a person standing still a) in front of the car b) behind the car?

Homework Equations


[fo/(vw+vo)] = [fs/(vw-vs)]

The Attempt at a Solution


a)
[fo/(vw+vo)] = [fs/(vw-vs)]
= [fo/350] = [1800/(350-25)]
= fo = 1938.5Hz

b)
[fo/(vw+vo)] = [fs/(vw-vs)]
= [fo/350] = [1800/(350+25)]
= fo = 1680Hz
 
Last edited:
Physics news on Phys.org


That looks fine for sound traveling at 350m/s.
 

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 'Collision of a bullet on a rod-string system: query'

Thread 'Collision of a bullet on a rod-string system: query'

In this question, I have a question. I am NOT trying to solve it, but it is just a conceptual question. Consider the point on the rod, which connects the string and the rod. My question: just before and after the collision, is ANGULAR momentum CONSERVED about this point? Lets call the point which connects the string and rod as P. Why am I asking this? : it is clear from the scenario that the point of concern, which connects the string and the rod, moves in a circular path due to the string...
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

What happens when a wave's wavelength is compressed by moving objects?
Replies
2
Views
2K
Find the speed of the source (Doppler Effect)
Replies
22
Views
6K
Doppler effect with moving source and observer
Replies
3
Views
3K
Doppler Shift/ Doppler effect HELP
Replies
5
Views
3K
Question on a doppler effect problem and equation
Replies
1
Views
4K
What is the relationship between the Doppler effect and the Hubble red shift?
Replies
6
Views
5K
Calculate difference between observed frequency and original frequency
Replies
11
Views
5K
How Does the Doppler Effect Influence the Frequency of an Ambulance Siren?
Replies
3
Views
5K
Doppler Effect: Moving Observer riding on moving source With reflection off wall
Replies
3
Views
6K
Calculating frequencies with the Doppler Effect
Replies
1
Views
3K

Hot Threads

Recent Insights

Back
Top