72. The maximum displacement of a particle executing S.H.M. corresponds to__________________?

A. zero potential energy and maximum kinetic energy
B. zero kinetic energy and maximum potential energy
C. maximum kinetic energy and maxi-mum potential energy
D. minimum kinetic energy and minimum potential energy
✅ The correct answer is option B.

74. A particle moves in a straight line and its position is defined by the equation x = 6 t2 – t3 where t is expressed in seconds and x in meters. The maximum velocity during the motion is_________________?

A. 6 m/sec
B. 12 m/sec
C. 24 m/sec
D. 48 m/sec
✅ The correct answer is option B.

76. Two balls of masses 3 kg and 6 kg are moving with velocities of 4 m/sec and 1 m/sec respectively, towards each other along the line of their centers. After impact the 3 kg ball comes to rest. This can happen only if the coefficient of restitution between the balls is____________________?

A. 2/3
B. 1/5
C. 3/5
D. 1/3
✅ The correct answer is option B.