The value of quantity G in the law of gravitation
(a) depends on mass of earth only
(b) depends on radius of earth only
(c) depends on both mass and radius of earth
(d) is independent of mass and radius of the earth
Law of gravitation gives the gravitational force between
(a) the earth and a point mass only
(b) the earth and Sun only
(c) any two bodies having some mass
(d) two charged bodies only
A boy is whirling a stone tied with a string in an horizontal circular path. If the string breaks, the stone
(a) will continue to move in the circular path
(b) will move along a straight line towards the centre of the circular path
(c) will move along a straight line tangential to the circular path
(d) will move along a straight line perpendicular to the circular path away from the boy
The gravitational force between two objects is F. If masses of both objects
are halved without changing distance between them, then the gravitational
force would become
(a) F/4 (b) F/2 (c) F (d) 2 F
The value of acceleration due to gravity
(a) is same on equator and poles
(b) is least on poles
(c) is least on equator
(d) increases from pole to equator
Two objects of different masses falling freely near the surface of moon would
(a) have same velocities at any instant
(b) have different accelerations
(c) experience forces of same magnitude
(d) undergo a change in their inertia
What is momentum? Write its SI unit. Interpret force in terms of momentum.
Represent the following graphically
(a) momentum versus velocity when mass is fixed.
(b) momentum versus mass when velocity is constant.
Water sprinkler used for grass lawns begins to rotate as soon as the water
is supplied. Explain the principle on which it works.
Two friends on roller-skates are standing 5 m apart facing each other. One
of them throws a ball of 2 kg towards the other, who catches it, How will
this activity affect the position of the two? Explain your answer