Physics-DPP-2-Gravitation
PHYSICS Topic: GRAVITATION Date:
1. A body which is initially at rest at a height R above the surface of the earth of radius R, falls freely towards the earth, then its velocity on reaching the surface of the earth is :
2. What additional velocity must be given to a satellite orbiting around earth with radius R to become free from earth’s gravitational field. Mass of earth is M.
(a)
GM 2 - 1 R
(b) GM 2R
2 - 1)
(c)
GM 3 - 1 R
(d)
GM 2 + 1 R
3. What impulse need to be given to a body of mass m, released from the surface of earth along a straight tunnel passing through centre of earth, at the centre of the earth, to bring it to rest. (Mass of earth M, radius of earth R)
(a)
m (b)
(c) m
(d) zero
4. A point P(R 3, 0, 0) lies on the axis of a ring of mass M and radius R. The ring is located in y-z plane with its centre at origin O. A small particle of mass m starts from P and reaches O under gravitational attraction only. Its speed at O will be :
(a)
(b)
(c)
(d)
5. A solid sphere of uniform density and radius R applies a gravitational force of attraction equal to F1 on a particle placed at a distance
R
2 R from the centre of the sphere. A spherical cavity of radius 2 is now made in the sphere as shown in the figure. The sphere with
F2
cavity now applies a gravitational force F2 on the same particle. The ratio is :
1
(a)
5
9 (b)
7
8 (c)
3 7
4 (d) 9
6. When a satellite going round the earth in a circular orbit of radius r and speed v loses some of its energy, then r and v change as :
(a) r and v both will increase (b) r and v both will decrease
(c) r will decrease and v will increase (d) r will increase and v will decrease
7. A particle hanging from a massless spring stretches it by 2 cm at earth’s surface. How much will the same particle stretch the spring at height 2624 km from the surface of earth ? (Radius of earth = 6400 km)
(a) 1 cm (b) 2 cm (c) 3 cm (d) 4 cm
PHYSICS Topic: GRAVITATION Date:
8. A satellite is revolving in a circular orbit whose radius is R work done by gravitatioanl force in the revolution is
(a) zero (b) 2 mGR2 (c) mg R2 (d) mg R
9. Three solid spheres each of mass m and radius R are released from the position shown in figure. The speed of any one sphere at the time of collision would be : -
10. A satellite of mass ms revolving in a circular orbit of radius rs around the earth of mass M has a total energy E. Then its angular momentum will be :
E
(a)
(b)
2m r 2
(c)
(d)
PHYSICS Topic: GRAVITATION Date:
1. (b)
2. (a) Answer Key
3. (a) 4. (a)
5. (d)
6. (c)
7. (a)
8. (a) 9. (d)
10. (c)
Comments
Post a Comment