Explanation:
In train's rest frame, the speed of photon is
and the proper length of the train is
. The time taken by the photon to cross the train is 
In ground frame, the speed of the photon is given as follows:


The speed of light or photon remains same in every frame of reference.
Now, the speed of train is very less as compared to the speed of photon so that
So that, 
The length contraction in the ground frame is given as follows:


Time taken by the photon to travel the length of the train in ground frame is .
Answer:
Induced emf in the coil,
Explanation:
Given that.
Number of turns in the coil, N = 200
Side of square, d = 18 cm = 0.18 m
The field changes linearly from 0 to 0.50 T in 0.80 s.
To find,
The magnitude of the induced emf in the coil while the field is changing.
Solution,
We know that due to change in the magnetic field, an emf gets induced in the coil. The formula of induced emf is given by :
= magnetic flux
A is the ares of square
So, the induced emf in the coil is 4.05 volts. Hence, this is the required solution.
The separation in time between the arrival of primary and secondary wave is called LAG TIME.
The time difference between the arrival of primary wave and secondary wave in a seismogram is called lag time. The primary wave always travels faster than the secondary wave, thus the difference between the two can be obtained by estimating the difference between the arrival time of the two waves/.
Answer:
<em>The end of the ramp is 38.416 m high</em>
Explanation:
<u>Horizontal Motion
</u>
When an object is thrown horizontally with an initial speed v and from a height h, it follows a curved path ruled by gravity.
The maximum horizontal distance traveled by the object can be calculated as follows:

If the maximum horizontal distance is known, we can solve the above equation for h:

The skier initiates the horizontal motion at v=25 m/s and lands at a distance d=70 m from the base of the ramp. The height is now calculated:


h= 38.416 m
The end of the ramp is 38.416 m high