Sunday 8 March 2020

PLUS ONE PHYSICS QUESTIONS AND ANSWERS

Chapter 8
           GRAVITATION

1. What would happen to  the duration of the year if the distance between the earth and  the sun gets doubled

Ans:- 2.828

2. The dimensional formula for gravitation constant is

Ans:- M -2 L 3 T -2

3.  The kinetic energy of a satellite is 2M joules  what is the total energy?

Ans:-  -2M Joules

4. The orbital velocity of a satellite at hight
r from the centre if earth is v. What will be the value of the escape velocity from the Same location ?

Ans:- 1.414 Vo

5. A body dropped from a satellite moved towards the surface of earth . State whether this statement true or False

Ans:- False.  A body dropped from a satellite moves along with the satellite

6. Work done to shift 1 kg of mass  from the surface of earth to infinity is

Ans:- gR

7.  A mass m is placed at centre of  allow sphere  of mass M and radius R .what is the gravitational force of mass m

Ans:- zero

8. The density of earth  is doubled keeping its radius constant . The acceleration due to gravity will be

Ans:- 1.96 m/s 2

9.  If the mass of the body  on the moon 13 denoted  by M m and that  on the earth by Me,then Mm=....................

Ans:- Mm=Me

10. A satellite is moved  out into orbit of larger radius. With of the following quantities associated with increases

Ans:- potential energy

11. State kelper 's law which you made use of there

Ans:- law of period- square of the time period of revaluation of a  plant  is proportional to the cube of semi - major axis of the ellipse . Traced by the plant

12. Velocity required for a satellite to remain in a particular orbit is called

Ans:- orbital velocity

13. Prove that total energy of n orbit satellite is equal to it is kinetic energy is magnitude

Ans:- total energy = KE+ PE = 1/2 mv2
           GMm/r
           V2=GM/r;so E=1/2GMm/r GMm/r
           =-1/2GMm/r
          E=-1/2GMm/r and K.E=1/2GMm/r

14.If satellite goes on lossing energy due to friction how will its orbital  speed and motion be affected

Ans:- Satellite comes closer to the earth with increasing speed





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