00:01
Here, an ambulance is traveling east bound at 102 km per hour.
00:07
So let it be denoted as vs, which is the speed of source.
00:11
Here, ambulance is the source.
00:14
Vs is given as 102 km per hour and it is traveling east.
00:20
Now we know that 1 km per hour is equals to 0 .278 meter per second.
00:31
Therefore, vs is equals to 102 km per hour into 0 .278 meter per second which is equals to 1 km per hour.
00:49
Now this is equal to 28 .36 meter per second.
00:56
So this is the speed of the ambulance or bissoles in meter per seconds.
01:01
Now the speed let the speed of the sound waves be denoted as v and we know that it is equals to 343 meter per second.
01:12
Now the velocity or the speed of the car driver or car is given as vo.
01:21
So here car is the observer here.
01:25
So we have vos 45 km per hour.
01:30
Now this is equals to 45 km per hour into 0 .278 meter per second which is equals to 1 km per hour.
01:45
This is equals to 12 .51 meter per second.
01:50
So this is the velocity of the car.
01:52
Now two cars are given.
01:54
One is going towards eastbound and the other one is westbound direction.
02:01
Now we have the siren frequency of the ambulance as 6 .5 into 10 power 2 hertz or this is equals to 650 hertz.
02:14
So this is the frequency of the siren in the ambulance.
02:18
So these are the given data.
02:21
Let us begin with subpart a.
02:24
Here we need to calculate the frequency observed by the east bound driver.
02:32
Eastbound driver as the ambulance approaches from behind.
02:39
So here we can use the expression f -dash equals.
02:43
For f -dash is the frequency observed by the east -bound driver.
02:47
F -dash is equals to f -into v -v -0 by v -v -s.
02:55
So here, v is the speed of the soundways.
02:59
V -0 is the speed of the observer.
03:03
And vs is the speed of the source.
03:05
Now substitute all the given values.
03:07
We have f as 650 hertz into 343 minus 12 .51 meter per second divided by 343 meter per second minus 28 .36 meter per second...