## Question

### Solution

Correct option is Escape velocity of a body from the earth’s surface is Where Me is the mass of earth and R­e is the radius of earth. If the mass of a planet be MP and radius RP, then the escape velocity from it will be  Given: Mp/Me = 1/4 and Rp/Re = ½.  #### SIMILAR QUESTIONS

Q1

A satellite is revolving in a circular orbit at a distance of 3400 km. calculate the orbital velocity and the period of revolution of the satellite. Radius of the earth = 6400 km and g = 9.8 ms –2.

Q2

(i) A satellite is revolving in an orbit close to the earth’s surface. Taking the radius of the earth as find the value of the orbital speed and the period of revolution of the satellite. (ii) What is the relationship of this orbital speed to the velocity required to send a body from the earth’s surface into space, never to return?

Q3

An artificial satellite revolving coplanar with the equator around the earth, appears stationary to an observer on the earth. Calculate the height of the satellite above the earth. Q4

An artificial satellite is revolving at a height of 500 km above the earth’s surface in a circular orbit, completing one revolution in 98 minutes. Calculate the mass of the earth. Given: Q5

If the period of revolution of an artificial satellite just above the earth be Tand the density of earth be then prove that ρT2 is a universal constant. Also calculate the value of this constant. Q6

A space-craft is launched in a circular orbit near the earth. How much more velocity will be given to the space-craft so that it will go beyond the attraction force of the earth. (Radius of the earth = 6400 km, g = 9.8 m/s2).

Q7

An artificial satellite of mass 200 kg revolves around the earth in an orbit of average radius 6670 km. Calculate its orbital kinetic energy, the gravitational potential energy and the total energy in the orbital.

(Mass of earth = 6.0 × 1024 kg, G = 6.67 × 10–11 Nm2 kg –2).

Q8

With what velocity must a body be thrown upward from the surface of the earth so that it reaches a height of 10 Re? Earth’s mass and G = 6.67 × 10 –11 Nm2kg–2.

Q9

A rocket is launched vertically from the surface of the earth with an initial velocity of 10 km s–1. How far above the surface of the earth would it go? Mass of the earth = 6.0 × 1024 kg, radius = 6400 km and G = 6.67 × 10 –11 Nm2 kg –2

Q10

A body is at a height equal to the radius of the earth from the surface of the earth. With what velocity be it thrown so that it goes out of the gravitational field of the earth? Given: N m2 kg–2.