Given below are two statements : one is labelled as Assertion A and the other is labelled as Reason R.

Assertion A : Body 'P' having mass M moving with speed 'u' has head – on collision elastically with another body 'Q' having mass  'm' initially at rest. If m << M, Body 'Q' will have a maximum speed equal to '2u' after collision.

Reason R : During elastic collision, the momentum and kinetic energy are both conserved. In the light of the above statements, choose the most appropriate answer from the options given below

A mass of 1 kg is suspended by a thread. It is lifted up with an acceleration of 4.9 ms^–2, and then lowered with an acceleration of 4.9 ms^–2 . The ratio of tensions in first case to second cases is (g = 9.8 ms^–2 )

Ball released from height 10 m strikes ground and rebounds height 5 m. Find impulse imparted by ground while collision, given mass of ball is 100 g. (Take g = 10 m/s²)

A ball is projected from ground with initial momentum p at an angle q. What is the magnitude of net change in linear momentum when it reaches at maximum height of journey?

When an elevator is moving downward with a increasing speed, the apparent weight of a body inside elevator

An insect of mass m = 2 g is inside a vertical drum of radius 1 m that is rotating with an angular velocity of 10 rad/s. If the insect does not fall off then the minimum coefficient of friction is