Speed of EM waves in a baseball park setting

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Homework Help Overview

The problem involves determining the time it takes for sound and electromagnetic waves to travel different distances in a baseball park setting. The scenario includes a batter hitting a ball, with sound traveling to a microphone and radio commentary being transmitted via satellite.

Discussion Character

  • Exploratory, Assumption checking

Approaches and Questions Raised

  • Participants discuss the need to calculate the time for sound to travel 17m and 140m, while also considering the time for electromagnetic waves to travel 75,000 km. There is uncertainty about how to incorporate temperature into the sound speed calculation and whether to use the speed of light for the electromagnetic wave.

Discussion Status

Some participants have provided guidance on the calculations needed, while others emphasize the importance of following forum rules regarding assistance. The discussion is ongoing, with various interpretations and approaches being explored.

Contextual Notes

Participants are navigating the constraints of the problem, including the need to factor in temperature for sound speed and the distances involved for both sound and electromagnetic waves. There is an emphasis on the forum's policy of guiding rather than providing direct answers.

monke
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Homework Statement


You and a friend are sitting in the outfield bleachers of a baseball park 140m from homeplate. The temperature is 20*C. YOur friend is listening to radio comentary with headphones while watching. There is a microphone located 17m from home plate to pick up the sound as the bat hits the ball. The sound travels as an EM wave a distance of 75000 KM by satilite from the ball park to the radio.

Homework Equations


When the batter hits the ball who will hear the "crack" of the bat first ? What is the shortest time interval between the bat hitting the ball and one of you hearing it ? How much later does the other person hear the sound?


The Attempt at a Solution



I am not sure where to start this problem. I know t can be found using d/c. However I do not know how to factor in the distance for the microphone and the satilites.

Should I be using c= 3x10^8 m/s?

any help would be fantastic

Thank you
 
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The batsman hears first!
The formula:
Velocity of sound in air = 331+(0.6)*temperature
I hope you can find a way to manipulate this (change 331 into 3*10^8 and 0.6 into..i don know.)
 
You must find out how long it takes the SOUND to travel 17m (make sure to correct for the temperature), and then add that to the time it takes for the LIGHT to travel 75,000km. Compare that to the time it takes the sound to travel 140m to the outfield bleachers.
 
Thank You Thank You :) your the best
 
Guys. We guide. We don't feed members the answers.

This is in the rules, which you agreed to.
On helping with questions: Any and all assistance given to homework assignments or textbook style exercises should be given only after the questioner has shown some effort in solving the problem. If no attempt is made then the questioner should be asked to provide one before any assistance is given. Under no circumstances should complete solutions be provided to a questioner, whether or not an attempt has been made.
https://www.physicsforums.com/showthread.php?t=414380
 

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