# Physics

posted by .

2 trains with 132Hz horns approach one another. The slower train has a speed of 25m/s. what is the speed of the fast train if an observer standing near the tracks between the trains hears a beat frequency of 5.2 Hz?

• Physics -

Fs = ((V + Vr) / (V + Vs))*Vo,
Fs = ((343 + O) / (343 + 25))132,
Fs = (343 / 368)132 = 123Hz = Frequency of slower train's horn,

Ff = 123 - 5.2 = 117.8 = Freq. of fast
train's horn.

Ff=((343 + 0) / (343 + Vs))132=117.8Hz.
45276 / (343 + Vs) = 117.8,
117.8(343 + Vs) = 45276,
343 + Vs = 45276 / 117.8 = 384.35,
Vs = 384.35 - 343 = 41.4m/s = Velocity
of suurce(fast train).

99

## Similar Questions

1. ### physics

A red train traveling at 72 km/h and a green train traveling at 144 km/h are headed toward each other along a straight, level track. When they are 720 m apart, each engineer sees the other's train and applies the brakes. The brakes …

Two trains on separate tracks move toward one another. Train 1 has a speed of 125 km/h and train 2 a speed of 100.0 km/h. Train 2 blows its horn, emitting a frequency of 500 Hz. What is the frequency heard by the engineer on train …
3. ### algebra

the speed of train A is 8 mph slower than the speed of train B. Train A travels 220 miles in the same time it takes train B to travel 260 miles. Find the speed of both trains. Speed of train A = Speed of train B =
4. ### math

When at rest, two trains have sirens that emit a frequency of 300 Hz. The trains travel toward one another and toward an observer stationed between them. One of the trains moves at 30.0 m/s, and the observer hears a beat frequency …
5. ### Physics

Two trains with 112-Hz horns approach one another. The slower of the two trains has a speed of 26 m/s. What is the speed of the faster train if an observer standing near the tracks between the trains hears a beat frequency of 4.7 Hz?
6. ### math

IF the speed of train A is 10 mph slower than train B. Train A travels 220 miles in the same time it takes train B to travel 270. What is the speed of both trains.
7. ### physics

Two trains are moving in opposite diections on parallel tracks and are appoaching a station. Horns on both trains are producing sound of frequency of 500Hz. One train is approaching at 32m/sec. What is the speed of the other train …
8. ### Physics

Two trains approach each other at a railroad crossing. Train 1 travels 80 km/h and Train 2 travels 50 km/h. They both sound their horns before passing each other, emitting sound waves at 300 Hz. The speed of sound is 343 m/s. At what …
9. ### Physics

A train blows its horn as it approaches a crossing. A.) if the train engineer observes a frequency of 125Hz and a stationary observer at the crossing observes a frequency of 132Hz, what is the speed of the train?
10. ### Physics

Two trains are running on parallel tracks., train A is faster than B.There is a box on each train of identical nature. But mass of box in train A is more than that of train B. If box is changed between the trains, what happens to speed …

More Similar Questions

Post a New Question