Sound to travel form the TV to the viewer

[zeshkani_usa]

Homework Statement

A celebrity holds a press conference, which is televised live. A television viewer hears the sound picked up by a microphone directly in front of the celebrity. This viewer is seated 2.9 m from the television set. A reporter at the press conference is located 5.2 m from the microphone and hears the words directly at the very same instant that the television viewer hears them. Using a value of 343 m/s for the speed of sound, determine the maximum distance between the television viewer and the celebrity.

Homework Equations

Let the time required for the sound to travel form the TV to the viewer be t1 = d1/v, where the symbols have their usual meaning. Let the time required for the sound to travel from the celebrity to the reporter be t2 = s2/v . The time required for the EM wave to travel to the viewer's set is t = s/c . Using the information given in the problem statement, construct a relationship between these three times.

The Attempt at a Solution

t1 = 8.45e-3 sec
t2 = 1.50e-2 sec
so should t = t1 + t2
then t1 + t2 = s/ 3.00e8 then just solve for s , i did solve for s this way but its wrong

 

[LowlyPion]

Homework Statement

A celebrity holds a press conference, which is televised live. A television viewer hears the sound picked up by a microphone directly in front of the celebrity. This viewer is seated 2.9 m from the television set. A reporter at the press conference is located 5.2 m from the microphone and hears the words directly at the very same instant that the television viewer hears them. Using a value of 343 m/s for the speed of sound, determine the maximum distance between the television viewer and the celebrity.

Homework Equations

Let the time required for the sound to travel form the TV to the viewer be t1 = d1/v, where the symbols have their usual meaning. Let the time required for the sound to travel from the celebrity to the reporter be t2 = s2/v . The time required for the EM wave to travel to the viewer's set is t = s/c . Using the information given in the problem statement, construct a relationship between these three times.

The Attempt at a Solution

t1 = 8.45e-3 sec
t2 = 1.50e-2 sec
so should t = t1 + t2
then t1 + t2 = s/ 3.00e8 then just solve for s , i did solve for s this way but its wrong

Why have you added the times together?

Isn't the difference what you're interested in?

 

[zeshkani_usa]

even adding or subtracting , its still the wrong asnwer

 

[LowlyPion]

even adding or subtracting , its still the wrong asnwer

There is no adding to get to the right answer.

Isn't time * velocity the distance though?

 

[madd_bm]

You have to divide the distances / speed of sound to get the two times, subtract, then multiply by speed of light.
remember: the reporter hears the sound at the exact same time as the viewer. you have to adjust the equation for the time that it takes both individuals to hear the sound and then adjust for the viewer who is "seeing" it.

d1/343 = t1

d2/343 = t2

(t1-t2) x 3e8


----exact same problem on hw...got it right.