A block is kept on a frictionless inclined surface with angle of inclination α. The incline is given an acceleration a to keep the block stationary. Then a is equal to

• g/tanα

• g cosecα

• g

• g

A spherical ball of mass 20 kg is stationary at the top of a hill of height 100 m. It rolls down a smooth surface to the ground, then climbs up another hill of height 30 m and finally rolls down to a horizontal base at a height of 20 m above the ground. The velocity attained by the ball is

• 40 m/s

• 20 m/s

• 10 m/s

• 10 m/s

A body A of mass M while falling vertically downwards under gravity breaks into two parts; a body B of mass 1/3 M and a body C of mass 2/3 M. The centre of mass of bodies B and C taken together shifts compared to that of body A towards

• depends on height of breaking

• does not shift

• body C

• body C

14.

A particle of mass 0.3 kg is subjected to a force F=−kx with k=15 N/m. What will be its initial acceleration if it is released from a point 20 cm away from the origin?

• 3 m/s²

• 15 m/s²

• 5 m/s²

• 5 m/s²

The block of mass M moving on the frictionless horizontal surface collides with a spring of spring constant K and compresses it by length L. The maximum momentum of the block after collision is

• 

• KL²/2M

• zero

• zero

A mass ‘m’ moves with a velocity v and collides inelastically with another identical mass. After collision, the 1^st mass moves with velocity v/√3 in a direction perpendicular to the initial direction of motion. Find the speed of the 2nd mass after collision

• v

• √3 v

• 2v/√3

• 2v/√3

Average density of the earth

• does not depend on g

• is a complex function of g

• is directly proportional to g

• is directly proportional to g

A body of mass m is accelerated uniformly from rest to a speed v in a time T. The instantaneous power delivered to the body as a function time is given by

Consider a car moving on a straight road with a speed of 100 m/s. The distance at which car can be stopped is [µ =k 0.5]

• 800 m

• 1000 m

• 600 m

• 600 m

A ‘T’ shaped object with dimensions shown in the figure, is lying on a smooth floor. A force F is applied at the point P parallel to AB, such that the object has only the translational motion without rotation. Find the location of P with respect to C

• 2

• 3

• 4

• 4