73. A cylinder will slip on an inclined plane of inclination 0 if the coefficient of static friction between plane and cylinder is_____________________?

A. less than (1/3) tan 0
B. less than (2/3) tan 0
C. less than (1/3) sin 6
D. less than (2/3) sin 6
✅ The correct answer is option A.

74. A stone was thrown vertically upwards from the ground with a velocity of 50 m/sec. After 5 seconds another stone was thrown vertically upwards from the same place. If both the stones strike the ground at the same time, then the velocity with which the second stone was thrown should be (Assume g = 10 m/sec2)______________________?

A. 15 m/sec
B. 25 m/sec
C. 40 m/sec
D. 50 m/sec
✅ The correct answer is option B.

75. One end of an elastic string of natural length / and modulus X is kept fixed while to the other end is attached a particle of mass m which is hanging freely under gravity. The particle is pulled down vertically through a distance x, held at rest and then released. The motion is___________________?

A. a simple harmonic motion
B. a rectilinear motion with constant speed
C. a damped oscillatory motion
D. none of the above
✅ The correct answer is option A.

80. 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.