1. Define the conservative and non-conservative forces? Give example of each?
2. A light body and a heavy body have same linear momentum. Which one has greater K.E?
3. Define spring constant of a spring?
4. What happens when a sphere collides head on elastically with a sphere of same mass initially at rest?
5. Derive an expression for K.E of a body of mass m moving with a velocity v by calculus method.
6. After bullet is fired, gun recoils. Compare the K.E. of bullet and the gun
7.If the momentum of the body is doubled by what percentage does its K.E changes?
8. A truck and a car are moving with the same K.E on a straight road. Their engines are simultaneously switched off which one will stop at a lesser distance?
9. What happens to the P.E of a bubble when it rises up in water?
10. In which type of collision there is maximum loss of energy?
Very Short Answer Type (2 Marks)
1. A bob is pulled sideway so that string becomes parallel to horizontal and released. Length of the pendulum is 2 m. If due to air resistance loss of energy is 10% what is the speed with which the bob arrives the lowest point?
2. 20 J work is required to stretch a spring through 0.1 m. Find the force constant of the spring. If the spring is stretched further through 0.1m calculate work done?
3. A pump on the ground floor of a building can pump up water to fill a tank of volume 30m3 in 15 min. If the tank is 40 m above the ground, how much electric power is consumed by the pump? The efficiency of the pump is 30%.
4. Find the work done if a particle moves from position r1 to a position r 2 under the effect of force, F ?
5. Show that in an elastic one dimensional collision the velocity of approach before collision is equal to velocity of separation after collision?
6. A spring is stretched by distance x by applying a force F. What will be the new force required to stretch the spring by 3x? Calculate the work done in increasing the extension?
7. Spring of a weighing machine is compressed by 1cm when a sand bag of mass 0.1 kg is dropped on it from a height 0.25m. From what height should the sand bag be dropped to cause a compression of 4cm?
8. Write the characteristics of the force during the elongation of a spring. Derive the relation for the P.E. stored when it is elongated by length. Draw the graphs to show the variation of potential energy and force with elongation?
9. How does a perfectly inelastic collision differ from perfectly elastic collision? Two particles of mass m1 and m2 having velocities u1 and u2 respectively make a head on collision. Derive the relation for their final velocities?
10. In lifting a 10 kg weight to a height of 2m, 250 Joule of energy is spent. Calculate the acceleration with which it was raised?(g=10m/s2 )
Short Answer Type 3 Marks Questions
1. Find the elevation of the outer tracks with respect to inner. So that the train could safely pass through the turn of radius 1km with a speed of 36km/hr. Separation between the tracks is 1.5m?
2. A block of mass m is placed over a smooth wedge of inclination θ. With what horizontal acceleration the wedge should be moved so that the block must remain stationery over it?
3. Involving friction prove that pulling is easier than pushing if both are done at the same angle.
4. In vertical circular motion if velocity at the lowermost point is √(6rg) where find the tension in the string where speed is minimum. Given that mass of the block attached to it is m?
5. An electrical water pump of 80% efficiency is used to lift water up to a height of 10m.Find mass of water which it could lift in 1hrour if the marked power was 500 watt?
6. A cycle is moving up the incline rising 1 in 100 with a const. velocity of 5m/sec. Find the instantaneous power developed by the cycle? 3. Find % change in K.E of body when its momentum is increased by 50%.
8. A light string passing over a light frictionless pulley is holding masses m and 2m at its either end. Find the velocity attained by the masses after 2 seconds.
9. Derive an expression for the centripetal force experienced by a body performing uniform circular motion.
10. A bullet of mass m moving with velocity u penetrates a wooden block of mass M suspended through a string from rigid support and comes to rest inside it. If length of the string is L find the angular deflection of the string.
Long Answer Type 5 Marks Questions
1. Two blocks of different masses are attached to the two ends of a light string passing over the frictionless and light pully. Prove that the potential energy of the bodies lost during the motion of the blocks is equal to the gain in their kinetic energies?
2. A locomotive of mass m starts moving so that its velocity v is changing according to the law v √(as), where a is constant and s is distance covered. Find the total work done by all the forces acting the locomotive during the first t seconds after the beginning of motion?
3. Derive an expression for the elastic potential energy of the stretched spring of spring constant k. Find the % change in the elastic potential energy of spring if its length is increased by 10%?
4.A force F = (- I +2 j +3 k) Newton is applied on a body and the is moved by a distance of 4 m along Z- axis .What is the work done by the force .
5. What is conservative force? Show that work done against conservative forces is a state function and not a path function. Also show that work done against it in a complete cycle is zero?
6. A body of man 10 kg moving with the velocity of 10m/s impinges the horizontal spring of spring constant 100 Nm-1 fixed at one end. Find the maximum compression of the spring? Which type of mechanical energy conversion has occurred? How does the answer in the first part changes when the body is moving on a rough surface?