Two particles A and B initially at rest, move towards each other under mutual force of attraction. At an instance when the speed of A is v and speed of B is 3v, the speed of centre of mass is :
A $$1 \mathrm{~kg}$$ object strikes a wall with velocity $$1 \mathrm{~m} \mathrm{~s}^{-1}$$ at an angle of $$60^{\circ}$$ with the wall and reflects at the same angle. If it remains in contact with wall for $$0.1 \mathrm{~s}$$, then the force exerted on the wall is :
The distance covered by a body of mass 5 g having linear momentum 0.3 kg m/s in 5 s is :
Given below are two statements : One is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A) : When a fire cracker (rocket) explodes in mid air, its fragments fly in such a way that they continue moving in the same path, which the fire cracker would have followed, had it not exploded.
Reason (R) : Explosion of cracker (rocket) occurs due to internal force only and no external force acts for this explosion.
In the light of the above statements, choose the most appropriate answer from the option given below