Thank you for registering.

One of our academic counsellors will contact you within 1 working day.

Please check your email for login details.
MY CART (5)

Use Coupon: CART20 and get 20% off on all online Study Material

ITEM
DETAILS
MRP
DISCOUNT
FINAL PRICE
Total Price: Rs.

There are no items in this cart.
Continue Shopping

bullets are fired at regular interval of 20s from a car A moving with 54km/h towards a car B which is approaching A with 30km/h if the speed of sound is330 m/s and that of wind is 10 m/s along BA ,then firing intervalobserved by a person in car B is

bullets are fired at regular interval of 20s from a car A moving with 54km/h towards a car B which is approaching A with 30km/h if the speed of sound is330 m/s and that of wind is 10 m/s along BA ,then firing intervalobserved by a person in car B is

Grade:12

2 Answers

Saurabh Koranglekar
askIITians Faculty 10341 Points
one year ago
576-890_1.PNG
Arun
25763 Points
one year ago
Dear student
 
Let initially when the first firing sound is made A abd B are S km aprt. Since air speed of 10 m/s is along the direction B to A, effective sound velocity is 340 m/s. if t is time taken by sound to travel S km, then t = (S/340) seconds. First firing sound will be heard by B after t seconds from the time when firing made at A. 
 
During the 20 second interval the distance between them reduces by 467 m. ( 84 km/hr = (5/18)×84 m/s; in  20 seconds (5/18)×84×20 = 467 m)
So the sound delay is reduced by 1.4 seconds. 
 
If sound is made at 0, 20, 40, 60....... seconds at A, B will hear at t, 20+t-1.4, 40+t-2.8, 60+t-4.2....   seconds
 
Thanks and regards

Think You Can Provide A Better Answer ?

Provide a better Answer & Earn Cool Goodies See our forum point policy

ASK QUESTION

Get your questions answered by the expert for free