EASY
NEET
IMPORTANT
Earn 100
Assertion: Kinetic energy is conserved in both, perfectly elastic and inelastic collisions.
Reason: Because both types of collisions are identical.
50% studentsanswered this correctly
Important Questions on Centre of Mass, Momentum and Collisions
HARD
NEET
IMPORTANT
Assertion: In the case of bullets fired from a gun, the ratio of the kinetic energy of gun and bullet is equal to the ratio of the mass of bullet and gun.
Reason: In firing, momentum is conserved.
EASY
NEET
IMPORTANT
Assertion: In an elastic collision of two billiards balls, the kinetic energy is not conserved during the short interval of time of collision between the balls.
Reason: Energy spent against friction does not follow the law of conservation of mechanical energy.
HARD
NEET
IMPORTANT
Assertion: A rocket launched vertically upward explodes at the highest point it reaches. The explosion produces three fragments with non-zero initial velocity. Then the initial velocity vectors of all the three fragments are in one plane.
Reason: For the sum of the momentum of three particles to be zero, all the three momentum vectors must be coplanar.
EASY
NEET
IMPORTANT
Assertion: Quick collisions are more violent than slow collisions.
Reason: Quick collisions are inelastic in nature.
EASY
NEET
IMPORTANT
Assertion: If a person jumps from a height with his legs rigid, then his ankle is more injured.
Reason: The force will be maximum on its ankle during the collision with the ground.
