০০। A 49 kg lady stands on a spring scale in an elevator. During the first 5 sec, starting from rest, the scale reads 69 kg. The velocity of the elevator will be
ক) 10 m/sec
খ) 15 m/sec
গ) 20 m/sec
ঘ) 25 m/sec.
০১। A 50 kg boy climbs up a 8 m rope in gymnasiam in 10 sec. The average power developed by the boy is approximately
ক) 400 watts
খ) 500 watts
গ) 4000 watts
ঘ) none of these.
০২। A ball is dropped from a height of 2.25 m on a smooth floor and rises to a height of 1.00 m after the bounce. The coefficient of restitution between the ball and the floor is
ক) 0.33
খ) 0.44
গ) 0.57
ঘ) 0.67
০৩। A ball moving with a velocity of 5 m/sec impinges a fixed plane at an angle of 45° and its direction after impact is equally inclined to the line of impact. If the coefficient of restitution is 0.5, the velocity of the ball after impact will be
ক) 0.5 m/sec
খ) 1.5 m/sec
গ) 2.5 m/sec
ঘ) 3.5 m/sec
ঙ) 4.5 m/sec.
০৪। A ball of mass 1 kg moving with a velocity of 2 m/sec collides a stationary ball of mass 2 kg and comes to rest after impact. The velocity of the second ball after impact will be
ক) zero
খ) 0.5 m/sec
গ) 1.0 m/sec
ঘ) 2.0 m/sec.
০৫। A ball of mass 250 g moving on a smooth horizontal table with a velocity of 10 m/sec hits an identical stationary ball B on the table. If the impact is perfectly plastic, the velocity of the ball B just after impact would be
ক) zero
খ) 5 m/sec
গ) 10 m/sec
ঘ) none of these.
০৬। A ball which is thrown upwards, returns to the ground describing a parabolic path during its flight
ক) vertical component of velocity remains constant
খ) horizontal component of velocity remains constant
গ) speed of the ball remains constant
ঘ) kinetic energy of the ball remains constant.
০৭। A block of weight 50 kg is placed on a horizontal plane. When a horizontal force of 18 kg is applied, the block is just on the point of motion. The angle of friction is
ক) 17° 48‘
খ) 18° 48‘
গ) 19° 48‘
ঘ) 20° 48‘
ঙ) 21° 48‘.
০৮। A body A of mass 6.6 kg which is lying on a horizontal platform 4.5 m from its edge is connected to the end of a light string whose other end is supporting a body of mass 3.2 kg as shown in below figure. If the friction between the platform and the body A is 1/3, the acceleration is
ক) 0.5 m/sec2
খ) 0.75 m/sec2
গ) 1.00 m/sec2
ঘ) 1.25 m/sec2.
০৯। A body is said to move with Simple Harmonic Motion if its acceleration, is
ক) always directed away from the centre, the point of reference
খ) proportional to the square of the distance from the point of reference
গ) proportional to the distance from the point of reference and directed towards it
ঘ) inversely proportion to the distance from the point of reference
ঙ) none of these.
১০। A body of weight 14 g appears to weight 13 g when weighed by a spring balance in a moving lift. The acceleration of the lift at that moment was
ক) 0.5 m/sec2
খ) 0.7 m/sec2
গ) 1 m/sec2
ঘ) 1 cm/sec2.
১১। A body of weight w placed on an inclined plane is acted upon by a force P parallel to the plane which causes the body just to move up the plane. If the angle of inclination of the plane is θ and angle of friction is φ, the minimum value of P, is
ক)
খ)
গ)
ঘ)
১২। A bullet weighing 200 g is fired horizontally with a velocity of 25 m/sec from a gun carried on a carriage which together with the gun weighs 100 kg. The velocity of recoil of the gun, will be
ক) 0.01 m/sec
খ) 0.05 m/sec
গ) 1.00 m/sec
ঘ) 1.5 m/see.
১৩। A cable loaded with 0.5 tonne per horizontal metre span is stretched between supports in the same horizontal line 400 m apart. If central dip is 20 m, the minimum tension in the cable, will be
ক) 200 tonnes at the centre
খ) 500 tonnes at the centre
গ) 200 tonnes at the right support
ঘ) 200 tonnes at the left support.
১৪। A geo-stationary satellite is one which orbits the earth with a velocity of rotation of
ক) moon
খ) earth
গ) sun
ঘ) pole.
১৫। A glass ball is shot to hit a wall from a point on a smooth floor. If the ball returns back to the point of projection in twice the time taken in reaching the wall, the coefficient of restitution between the glass ball and the wall is
ক) 0.25
খ) 0.33
গ) 0.40
ঘ) 0.50
ঙ) 0.55
১৬। A heavy ladder resting on a floor and against a vertical wall may not be in equilibrium, if
ক) floor is smooth and the wall is rough
খ) floor is rough and the wall is smooth
গ) floor and wall both are smooth surfaces
ঘ) floor and wall both are rough surfaces.
১৭। A load of 500 kg was lifted through a distance of 13 cm. by an effort of 25 kg which moved through a distance of 650 cm. The efficiency of the lifting machine is
ক) 50%
খ) 40%
গ) 55%
ঘ) 30%.
১৮। A load of 500 kg was lifted through a distance of 13 cm. by an effort of 25 kg which moved through a distance of 650 cm. The mechanical advantage of the lifting machine is
ক) 15
খ) 18
গ) 20
ঘ) 26.
১৯। A load of 500 kg was lifted through a distance of 13 cm. by an effort of 25 kg which moved through a distance of 650 cm. The velocity ratio of the lifting machine is