19. A , body hurry in a freely falling elevator, drops a ball. He will observe that the ball:

(a) falls with an acceleration equal to 'g moves up with constant speed.

remans stationary. behaves as a projectile and will stríke opposite to the wall of the elevator. When the frame of reference of an observer falls freely under gravity,

apparent weight of the bodíes in it will. remain unchangcd. decrease. The apparent between on aweight of a body orbiting the earth is always ipcreasv Ad bc zcro. increases equal to the true weight zero decreases 22. The value of 'g' at the center the earth is (a) infinite (b) 9.8ms Ld zero -9.8 mTwo bodies, kept close to each other, when allowed to fall simultaneously,

they fall to the ground independently. The do not move toward each otherbecause; (a) the force of attraction does not obey law of gravitation. (b) the gravitational force between the bodies is extremely weak. the earth, being more massive, exerts larger force of attraction both b and The state of weightlessness can be achieved by(a) keeping the reference frame at rest. (b) keeping the veiocity of the reference frame uniform. (c)keeping of the reference frame uniform vibrating. the free fall motion of the reference frame.

Apparent weight of a body depends upon the reference frame's.

(a) velocity

C) acceleration

(b) inertia

(d) momentum :_

The apparent weiglht of a person, standing in an elevator which is moving a car 

down with uniform acceleration, will be

a) the same as that on the surface of the earth. b) greater than his weight on the surface of the earth. lass than his weight on the surface of the earth. double his weight at rest. tificial gravity is produced in a spacecraft to ncrease weight of the astronaut. 9se weight of the astronaut the state of weightlessness. force of friction.