# Physics Exercises/Gravity

1. If ve and vo denotes the escape velocity and orbital velocity of a satellite corresponding to a circular orbit of radius R, then
1. $v_{e}=v_{o}$ 2. $v_{e}=1.74\times v_{o}$ 3. $v_{e}=v_{o}/1.74$ 4. $v_{e}$ and $v_{o}$ are not related
2. the orbital traced by planet around a star is in general
1. a circle
2. an ellipse
3. a parabola
4. a straight line
3. the period of a satellite in a circular orbit of radius R is T.What is the period of another satellite in a circular orbit of radius 4R
1. 4T
2. T/8
3. T/4
4. 8T
4. A satellite is moving around the earth in a circular orbit.Which of the following statement is correct
1. it is moving with a constant speed
2. it is falling freely towards earth
3. its velocity keeps on increasing
4. it is falling freely towards the earth its velocity keeps on increasing
5. a satellite is revolving round the earth in a circular orbit of radius R. work done by gravitational force in one revolution is
1. zero
2. $2mgR^{2}$ 3. $mgR^{2}$ 4. $mgR$ 6. What is the pressure in the center of the Earth assuming the constant density.