What happens to the P.E. when an elevator loses in coming down from the top of a building to a stop at the ground floor?/

Why are tall building provided with metallic rods, running from the top of building to the ground?

What happens to the wavelength of light when it goes from rarer to denser medium?

From a point P on the ground the angle of elevation of the top of a 10 m tall building is 30^@ . A flag is hoisted at the top of the building and the angle of elevation of the top of the flagstaff from P is 45^@ . Find the length of the flagstaff.

From a point P on the ground the angle of elevation of the top of a 10 m tall building is 30^@ .A flag is hoisted at the top of the building and the angle of elevation of the top of the flagstaff from P is 45^@ . Find the length of the flagstaff and the distance of the building from the point P. (You may take sqrt3 = 1.732)

The angles of elevation and depression of the top and bottom of a light-house from the top of a building 60 m high are 30^@ and 60^@ respectively. Find the difference between the heights of the light-house and the building

The angles of elevation and depression of the top and bottom of a light-house from the top of a building 60 m high are 30^@ and 60^@ respectively. Find difference between the light-house and the building.

The angle of elevation of the top of a building from the foot of the tower is 30^@ and the angle of elevation of the top of the tower from the foot of the building is 60^@ . If the tower is 50 m high, find the height of the building.

What happens to the thickness of the depletion layer in p-n junciton when reverse bias is increased?