# Two balls of masses and are suspended from point by two equal inextensible threads, each of length m. Ball of mass is drawn aside and held at the same level as but at a distance from , as shown in Fig. When ball is released, it collides elastically with the stationary ball of mass  Velocity with which the ball of mass collides with the other ball is 1 m/s b) 2 m/s c) 3 m/s d) 4 m/s

## Question ID - 101265 :- Two balls of masses and are suspended from point by two equal inextensible threads, each of length m. Ball of mass is drawn aside and held at the same level as but at a distance from , as shown in Fig. When ball is released, it collides elastically with the stationary ball of mass  Velocity with which the ball of mass collides with the other ball is 1 m/s b) 2 m/s c) 3 m/s d) 4 m/s

3537

(d)

Ball of mass falls freely till thread becomes taut. At that instant inclination of the thread with the vertical be given by Ball of mass falls freely through height  Velocity of this ball at this instant is It can be resolved into two components

i. , along the thread. But thread is inextensible, hence this component decreases to zero (due to tension developed in the thread)

ii. , perpendicular to the thread. Due to this component ball starts to move along a circle whose centre is at According to law of conservation of energy,

Kinetic energy of ball just before collision = Its kinetic energy at + Further loss of its potential energy  According to law of conservation of momentum, And coefficient of restitution, Substituting and  the height to which it rises is Next Question :

Following question is based on analogy.  There are two pairs of letters combination in each question.  The first (left hand side) pair has some relationship between its members.  In the second pair, one member is missing.  Find this out from the options such that this pair has similar relationship as the first pair.

 PRINCIPAL : LAPICNIRP : : ADOLESCENCE : ? (a) ECNCESELODA (b) ECNECSLEODA (c) ECNSCEELODA (d) ECNECSELODA 