1
KCET 2022
+1
-0

The centre of mass of an extended body on the surface of the earth and its centre of gravity

A
are always at the same point only for spherical bodies.
B
can never be at the same point.
C
centre of mass coincides with the centre of gravity of a body if the size of the body is negligible as compared to the size (or radius) of the earth.
D
are always at the same point for any size of the body.
2
KCET 2021
+1
-0

A $$1 \mathrm{~kg}$$ ball moving at $$12 \mathrm{~ms}^{-1}$$ collides with a $$2 \mathrm{~kg}$$ ball moving in opposite direction at $$24 \mathrm{~ms}^{-1}$$. If the coefficient of restitution is $$2 / 3$$, then their velocities after the collision are

A
$$-4 \mathrm{~ms}^{-1},-28 \mathrm{~ms}^{-1}$$
B
$$-28 \mathrm{~ms}^{-1},-4 \mathrm{~ms}^{-1}$$
C
$$4 \mathrm{~ms}^{-1}, 28 \mathrm{~ms}^{-1}$$
D
$$28 \mathrm{~ms}^{-1}, 4 \mathrm{~ms}^{-1}$$
3
KCET 2021
+1
-0

A ball hits the floor and rebounds after an inelastic collision. In this case

A
the momentum of the ball is conserved
B
the mechanical energy of the ball is conserved
C
the total momentum of the ball and the earth is conserved
D
the total mechanical energy of the ball and the earth is conserved
EXAM MAP
Medical
NEET