Answer:

Explanation:
As we know that train is initially moving with the speed

now we know that

now the final speed of the train when it crossed the crossing


now we can use kinematics here



Now the time to cross that junction is given as



Answer: When an ambulance passes with its siren blaring, you hear the pitch of the siren change: as it approaches, the siren’s pitch sounds higher than when it is moving away from you. This change is a common physical demonstration of the Doppler effect.
Explanation:
Answer:
0.767m
Explanation:
We are given that the time interval between each droplet is equal.
We are also given that the fourth drop is just dripping from the shower when the first hits the floor.
If they fall at the same time interval and we know that the distance between the shower head and floor are the same, they must therefore fall at the same velocity.
The distance between each drop has to be the same given that they fall at equal time intervals.
Let this distance be x.
We can then partition the entire height of the system into three parts (as shown in the diagram).
Hence, we can say that:
x + x + x = 2.3m
3x = 2.3m
=> x = 2.3/3 = 0.767m
Therefore, at the time the first drop hits the floor, the third drop is only 0.767 m below the shower head.