Work, Energy an...

A block C of mass m is moving with velocity v_o and collides elastically with block A of mass m and connected to another block B of mass 2m through spring constant k. What is k, if x_o is compression of spring when velocity of A and B is same ?

Consider the following statements A and B and identify the correct answer.
A. In an elastic collision, if a body suffers a head on collision with another of same mass at rest, the first body comes to rest while the other starts moving with the velocity of the first one.
B. Two bodies of equal mass suffering a head on elastic collision merely exchanges their velocities.

A vertical spring with force constant k is fixed on a table. A ball of mass mat a height h above the free upper end of the spring falls vertically on the spring, so that the spring is compressed by a distance d. The net work done in the process is

A spring of natural length AB is extended upto C. if spring constant is k, then energy stored is

A lorry and a car moving with the same kinetic energy are brought to rest by the application of brakes which provide equal retarding forces. Which of them will come to rest in a shorter distance ?

A motor cycle is moving along a straight horizontal road with a speed V₀. If the coefficient of friction between the tyres and the road is µ , the short distance in which the car can be stopped is :

A particle moves on a rough horizontal ground with some initial velocity v₀. If 3/4 th of its K.E is lost in friction in time t₀, the coefficient of friction between the particle and the ground is