Saturday, 14 January 2017


1. The moment of inertia of two rotating bodies A and B are IA and IB(IA > IB) and their angular momenta
    are equal. Which one has a greater kinetic energy?
2. What is the value of torque on the planet due to the gravitational force of sun?
3. Name two factors which determine whether a planet would have atmosphere or not.
4. A satellite does not require any fuel to orbit the earth. Why?                                         
5. Why is it easier to swim in sea water than in the river water?
6. From a uniform disc of radius R, a circular disc of radius R/2 is cut out. The centre of the hole is at R/2   
   from the   centre of original disc. Locate the centre of gravity of the resultant flat body
   If the radius of the earth were to decrease by 1%, keeping its mass same, how will the acceleration due   
   to gravity change?
7. A metre stick is balanced on a knife edge at its centre. When two coins, each of mass 5 g are put one
  on top of the other at the 12.0 cm mark, the stick is found to be balanced at 45.0 cm, what is the mass   
  of the meter stick?
8. How will you distinguish between a hardboiled egg and a raw egg by spinning it on a table top?
9. Give the physical significance of moment of inertia.
10. Define gravitational potential. Give its SI units.
11. A disc 8.00 cm in radius rotates at a constant rate of 1 200 rev/min about its central axis. Determine
    (a) its angular speed, (b) the linear speed at a point 3.00 cm from its center, (c) the radial acceleration  
       of a point on the rim, and (d) the total distance a point on the rim moves in 2.00 s.
12. A weight of 50.0 N is attached to the free end of a light string wrapped around a reel with a radius of
      0.250 m and a mass of 3.00 kg. The reel is a solid disk, free to rotate in a vertical plane about the      
     horizontal axis passing through its center. The weight is released 6.00 m above the floor.
(a) Determine the tension in the string, the acceleration of the mass, and the speed with which the
    weight hits the floor. (b) Find the speed calculated inpart (a), using the principle of conservation of    
13. A cylinder of mass 10.0 kg rolls without slipping on a horizontal surface. At the instant its center of
     mass has a speed of 10.0 m/s, determine (a) the translational kinetic energy of its center of mass, (b)   
     the rotational energy about its center of mass, and (c) its total energy.
14.Define a) Young’s Modulus b) Shear Modulus c) Bulk modulus
15. An airliner arrives at the terminal, and its engines are shut off. The rotor of one of the engines has an
     initial clockwise angular speed of 2 000 rad/s. The engine’s rotation slows with an angular        
     acceleration of magnitude 80.0 rad/s2. (a) Determine the angular speed after10.0 s. (b) How long
     does it take for the rotor to comes to rest?

16.Explain how hydraulic lift works

17.A satellite of the Earth has a mass of 100 kg and is at an altitude of 2.00 x106 m. (a) What is the
     potential energy of the satellite–Earth system? (b) What is the magnitude of the gravitational force   
    exerted by the Earth on the satellite? (c) What force does the satellite exert on the Earth

18.The manual of a car instructs the owner to inflate the tyres to a pressure of 200 k pa. (a) What is the
     recommended gauge pressure? (b) What is the recommended absolute pressure (c) If, after the   
     required inflation of the tyres, the car is driven to a mountain peak where the atmospheric pressure is
    10% below that at sea level, what will the tyre gauge read?
19. Prove that the elastic potential energy per unit volume is equal to1/2×stress × strain.
     Which is more elastic steel or rubber. Explain.

20. The mass of planet Jupiter is 1.9 × 1027 kg and that of the sun is 1.99 × 1030kg. The mean distance of
     Jupiter from the Sun is 7.8 × 1011m. Calculate gravitational force which sun exerts on Jupiter, and the
     speed of Jupiter.

21.Explain if the ice on the polar caps of the earth melts, how will it affect the duration of the day?

22. Obtain an expression for the work done by a torque. Hence write the expression for power.
23.Kamal helps others.once,hand of his friend got wounded. He went to a doctor and an injection of
     tetanus is given to his friend.
(i)                  What values do you appreciate in Kamal?
(ii)                The nurse filled two syringes of different bores. Diameter of small syringe is 2cm and of larger piston is 3 cm.Which syringe will hurt  more to his friend if the same force is applied on both
24.a) Prove that the rate of change of angular momentum of a system of particles about a reference
         point is equal to the net torque acting on the system.
        b)Derive the relation between angular momentum and moment of Inertia for rigid body rotating
         about fixed axis
       Obtain an expression for linear acceleration of a cylinder rolling down on inclined plane and hence    
       find condition for cylinder to roll down inclined plane without slipping
25.a) Define escape velocity obtain an expression for escape velocity of a body from the surface of
      b) Derive expression for the orbital velocity of a satellite and its time period. What is a geostatinary
        satellite?. Obtain the expression for the height of the geostationary satellite.
      Explain Kepler”s Planetary motion for a) Law of orbits b) Law of areas c) Law of Periods and  Prove
     law  of Periods
26. Draw and discuss stress versus strain graph, explaining clearly the terms elastic limit, permanent
    set, proportionality limit ,Elastic region, Plastic region and Fracture point

    a) State Pascal’s law and prove it. b) Show how pressure varies with depth.