A man stands on vertical tower of height 20m. Calculate the distance upto which he will be able to see the surface of the earth. Given radiur of earth is `6.4xx10^3km`.

A planet's year is 11 times the earth's year. Calculate the distance of this planet from the sun if the distance of the earth is 1.50xx10^8 km from the sun.

The transmitting antenna at the top of a tower has a height of 32m. The height of the receiving antenna is 50m. What is the maximum distance between them for satisfactory LOS mode Communication? Radius of earth is 6.4xx10^3km .

What is the magnitude of the gravitational force between the earth and a 1 kg object on its surface? (Mass of the earth is 6 x 10^24 kg and radius of the earth 6.4 x 10^6 m.)

Calculate the excess of pressure in a soap bubble of radius 3xx10^-3 m surface tension of the soap solution is 20xx10^-3 N/m.

A satellite orbits the earth at a height of 400 km above the surface. How much energy must be expended to rocket the satellite out of the earth’s gravitational influence? Mass of the satellite = 200 kg, mass of the earth = 6.0 xx10^24 kg, radius of the earth = 6.4 xx10^6 m, G = 6.67 x 10^-11 N m^2 kg ^-2 .

As you have learnt in the text, a geostationary satellite orbits the earth at a height of nearly 36,000 km from the surface of the earth. What is the potential due to earth’s gravity at the site of this satellite? (Take the potential energy at infinity to be zero). Mass of the earth = 6.0 xx 10^24 kg, radius = 6400 km

A rocket is fired from the earth towards the sun. At what distance form the earth's centre is the gravitational force on the rocket zero? Mass of the sun = 2 xx 10^20 kg and mass of earth = 6 xx 10^24 kg and orbital radius 1.5 xx 10^-8 km.

A man standing on the deck of a ship which is 10 m above the water level, observes the angle of elevation of the top of a hill as 60° and angle of depression of the base of a hill as 30°. Calculate the distance of the hill from the ship and the height of the hill.