This is the Doppler effect.
1. As the sound leaves the horn the sound waves are at first close to each other and as they move outwards they become further apart. The closer the sound waves are the louder the noise.
As the car gets the closer the sound waves get closer, so the horn becomes louder.
2. As the horn moves away, the sound waves become less frequent, causing the pitch to get lower.
Answer:
317.52 mi/hr
Explanation:
First convert Meters into miles as the answer is required in miles/ h
1000m = 0.62 mi
Now, convert second into hours
7.45s = 0.0001 hr
The speed of the boat would be
v = 0.62/0.0001
=317.52 mi/hr
Answer:
18.03 s
Explanation:
We have two different types of motions, the criminal moves with uniform motion while the police do it with uniformly accelerated motion. Therefore we will use the equations of these cases. We know that by the time the police reach the criminal they will have traveled the same distance.
The distance between the police and the criminal when the first one starts the persecution is 0, its initial speed is also zero. So:
Equalizing these two equations and solving for t:
Final speed = initial speed + (acceleration x time)
(final speed - initial speed) = acceleration x time
Time = (final speed - initial speed) / acceleration
