Q.11)-The function of ball bearings in a wheel is
  • To increase friction
  • To convert kinetic friction into rolling friction
  • To convert static friction into kinetic friction
  • Just for convenience
Q.12)-A sphere rolls down on two inclined planes of different angles but same heights, it does so
  • In the same time
  • With the same speed
  • In the same time with the same speed
  • In the same time with the same kinetic energy
Q.13)-An athlete runs before long jump to get advantage on
  • Inertia of motion
  • Frictional force
  • Moment of a force
  • Principle of moments
Q.14)-A pilot has to release the bomb to hit a target
  • Right above the target
  • Beyond the target
  • Before the target
  • None of these
Q.15)-A bomb at rest explodes into a large number of tiny fragments.The total momentum of all the fragments.
  • Is zero
  • Depends on the total mass of all the fragments
  • Depends on the speeds of various fragments
  • Is infinity
Q.16)-The slope of a velocity time graph represents
  • Acceleration
  • Displacement
  • Distance
  • Speed
Q.17)-Railway tracks are banked on curves so that
  • Necessary centrifugal force may be obtained from the horizontal component of the weight of the train
  • No frictional force may be produced between the tracks and the wheels of the train
  • Necessary centripetal force may be obtained from the horizontal component of the weight of the train
  • The train may not fall down inwards
Q.18)- When a running car stops suddenly the passengers tends to lean forward because of
  • Centrifugal force
  • Inetria of rest
  • Inertia of motion
  • Gravitational force
Q.19)-A metal ball and a rubber ball, both having the same mass, strike a wall normally with the same velocity.the rubber ball rebounds and the metal ball does not rebound. It can be concluded that
  • The rubber ball suffers greater change in momentum
  • The metal ball suffers greater change in momentum
  • Both suffer the same change in momentum
  • The initial momentum of the rubber ball is greater than that of the metal ball
Q.20)-The motion of the wheels of a bullock cart while moving on the road is an example of
  • Oscillatory and rotatory motion
  • Oscillatory and translatory motion
  • Translatory and rotatory motion
  • Translatory motion only