1. A particle is projected from point A with velocity u at an angle α with horizontal. In its parabolic path, at point P the particle is moving at right angles to its initial direction of projection. Its velocity at P is
A) u tan α B) u cot α
C) u cos α D) u cosec α
2. The angular speed of the second’s hand of a clock is
A) (1/60) rad/s B) (π/60) rad/s
C) (2π/60) rad/s D) (360/60) rad/s
3. In a thermo dynamical process pressure of fixed mass of gas is changed in such a way that the gas molecules give out 30 J of heat and 10 J of work is done on the gas. If the internal energy of the gas was 40 J, the final internal energy will be
A) zero B) 80 J C) 20 J D) – 20 J
4. A body travelling along a straight line traversed one third of the total distance with a velocity 4 m/s. The remaining part of the distance was covered with a velocity 2 m/s for half the time and with velocity 6 m/s for
the other half of time. The mean velocity averaged over the whole time of motion is
A) 5 m/s B) 4 m/s C) 4.5 m/s D) 3.5m/s
5. A body is placed on a rough inclined plane of inclination θ. As the angle θ is increased from 0o to 90o the contact force between the block and the plane
A) remains constant
B) first remains constant then decreases
C) first decreases then increases
D) first increases then decreases
Key: 1)B 2)C 3)C 4)B 5)B