Speed of EM waves in a baseball park setting

AI Thread Summary
In a baseball park scenario, sound and electromagnetic (EM) waves travel at different speeds, affecting who hears the bat's crack first. The speed of sound in air is influenced by temperature, calculated using the formula 331 + (0.6 * temperature). To determine the time difference between when the batter hears the sound and when the friend in the bleachers hears it, one must calculate the sound's travel time to the microphone and then to the bleachers, compared to the EM wave's travel time from the park to the radio. The discussion emphasizes the importance of showing effort in solving the problem before seeking assistance. Understanding these principles is crucial for accurately answering the homework questions.
monke
Messages
20
Reaction score
0

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
 
Physics news on Phys.org
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
 

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

A batter hits a baseball motion and velocity problem
Replies
2
Views
6K
What Determines the Velocity of a Baseball After Being Hit?
Replies
1
Views
9K
A question about the speed of EM and mechanical waves
Replies
3
Views
4K
Calculating Distance from Sound and Light Speeds
Replies
3
Views
6K

Hot Threads

Recent Insights

Back
Top