Q.1
A dish of mass 10 gm is kept floating horizontally in air by firing bullets each of mass 5gm with the same velocity at the rate of 10 bullets per second and the bullets rebounds with same speed in opposite direction , then the velocity of each bullet at the time of impact is
  • a) 196 cm/s
  • b) 98 cm/sec
  • c) 49 cm/sec
  • d) 392 cm/sec
Q.2
A motor-cyclist moving with a velocity of 72km/hr on a flat road takes a turn on the road at a point where the radius of curvature of the road is 20 meter. The acceleration due to gravity is 10m -In order to avoid sliding, he must not bend with respect to the vertical plane by an angle greater than.. [AFMC 2001]
  • a) Θ=tan⁻¹(4)
  • b) Θ=tan⁻¹(25.91)
  • c) Θ=tan⁻¹(2)
  • d) Θ=tan⁻¹(6)
Q.3
A cyclist is moving in a circular track of radius 80m with velocity v=36 km/hr. He has to lean from the vertical approximately through an angle ( take g=10 m/s2)( kerala PET 2004)
  • a) tan⁻¹(4)
  • b) tan⁻¹(1/8)
  • c)tan⁻¹(1/4)
  • d)tan⁻¹(2)
Q.4
A machine gun is mounted on a 2000kg car on a horizontal frictionless surface. At some instant the gun fires a bullets of mass 10gm with velocity of 500 m/sec with respect to the car. The number of bullets fired per second is ten. The average thrust on the system is
  • a)550 N
  • b) 50 N
  • c)250 N
  • d)250 dynes
Q.5
A 30 gm bullet initially travelling at 120 m/s penetrates 12 cm into a wooden block. The average resistance exerted by the wooden block is. [AFMC 1999; CPMT]
  • a)2850N
  • b)2000N
  • c)2200 N
  • d)1800 N
Q.6
An inclined plane makes an angle 30° with the horizontal. A groove OA=5m cut in the plane makes an angle 30° with OX. A small smooth cylinder is free to slide down under the influence of gravity. The time taken by the cylinder to reach from A to O is ( g=m/s2)
ch-4_que_no-173_img_no1.png
  • a)4 s
  • b) 2 s
  • c)2√2 s
  • d)1 s
0 h : 0 m : 1 s