The radius of the earth is 6400 km, the order of magnitude is

A cosmonaut is orbiting the earth in a spacecraft at an altitude h =630km with a speed of 8kms^(-2) . If the radius of the earth is 6400km, the acceleration of the cosmonaut is

The radius of the Earth is 6400 km. If the height of an antenna is 500 m, then its range is

The radius of the Earth is 6400 km. If the height of an antenna is 500 m, then its range is

If the TV telecast is to cover a radius of 120 km ( Given , the radius of the earth = 6400 km ), the height of the transmitting antenna is

The radius of Earth is 6400 km. If the height of an antenna is 500 m , then its range is

If atmospheric electric field is approximately 150 volt/m and radius of the earth is 6400 km, then the total charge on the earth's surface is

If atmospheric electric field is approximately 150 volt/m and radius of the earth is 6400 km, then the total charge on the earth's surface is