1. Name one technique employed for estimating the age of fossils and age of rocks.

2. What is the work done on an electron revolving around the Nucleus?

3. Two particles A and B start moving towards each other with velocities 10ms-1 and 15ms-1 respectively from the separation of 500m. What is the displacement of A w.r.t. B after 4 seconds?

4. If you place a brick on a smooth floor, you can move it easily by pushing it with your foot. Yet if you kick the brick, you will hurt your foot. Why?

5. A body is projected at an angle of 600 with the horizontal with momentum p. What is the magnitude of its momentum at its highest point?

6. Proper inflation of tires of vehicles saves fuel. Why? 7. A body is moving along a circular path such that its speed is always remains constant. Should there be force acting on the body?

8. A particle is moving along a circular track of radius 1m with uniform speed. What is the ratio of the distance covered and the displacement in half revolution? 9. What is the maximum percentage error in the measurement of kinetic energy if the percentage errors in mass and speed are 2% and 3% respectively? 10. The kinetic energy of a body is increased by 21%. What is the percentage increase in the linear momentum of the body? Or Momentum of a body is increased by 100%. Find out the percentage change in kinetic energy of the body 11. Two forces whose magnitude is in the ratio of 3:5 give a resultant of 35 N. If the angle of inclination be 600, calculate the magnitude of each force. 12. Given below are some examples of motion. State in each case if the motion is one, two are there dimensional (a) A kite flying on a windy day (b) A speeding car on a long straight highway. (c) An insect crawling on a globe. (d) A carom coin rebounding from the side of the board. 13. What are concurrent forces? Obtain a condition for the equilibrium of three concurrent forces. 14. Define angle of friction and angle of response. Derive a relation between them. 15. The equation of trajectory of an oblique projectile is Y =√3x-gx2/2. What are the initial velocity and the angle ofprojection of the projectile? 16. What is rolling friction? Explain the cause of rolling friction? 17. Prove that the vectors i + 2j +3k and 2i j are perpendicular to each other. 18. It is easier to pull a cart than to push it. Explain with necessary vector diagram. 19. Time period of an oscillating drop of radius r, density ρ and surface tensions is t= √(ρr3/s). Check the correctness of therelation. Given: k is dimensionless. 20. Obtain by the method of dimensional analysis an expression for the surface tension of a liquid rising in a capillary tube. Assume that the surface tension (force per unit length) depends on the mass m, pressure P of the liquid and radius r of a capillary tube. The constant K = ½. Or The depth x to which a bullet penetrates in a human body depends upon (i) coefficient of elasticity η(pressure units) and kinetic energyK. Establish the relation among these quantities by the method of dimensional analysis. 21. Find the value of 60 joule/minute on a system which has 100g, 100cm and 1min as fundamental units. 22. A body dropped from the top of a tower falls through 40m during the last two seconds of its fall. What is the height of the tower? 23. Three points P, Q and R are in a vertical line such that PQ = QR. A ball at P is allowed to fall freely. What is the ratio of the times of descent through PQ and QR?24. The ceiling of a long hall is 25m high. What is the maximum horizontal distance that a ball thrown with a speed of 40ms-1 can go without hitting the ceiling of the hall? 25. A batsman deflects a ball by an angle of 450 with out changing its initial speed which is equal to 54kmph. What is the impulse imparted to the ball? [Mass of the ball is 0.15kg.] 26. State Newtons laws of motion. Show that it gives the measure of force. Also show that Newtons second law of motion is the only real law of motion. 27. A disc revolves with a speed of 33⅓ rpm and has a radius of 15cm. Two coins are placed at 4cm and 14cm away from the centre of the record. If the coefficient of friction between the coins and the record is 0.15, which of the coins will revolve with the record? 28. a)Two resistances R1=100 ± 3ohms and R2= 200 ± 4 ohms are connected (i) in series (ii) in parallel. Find the net resistance in each combination with error limits. b)Write four limitations of dimensional analysis. OR a)How can you calculate the radius of the atom by making use of Avogadros hypothesis? b)Explain how the distance of an aeroplane is measured using Radar. 29. a)Prove that the minimum velocity of a particle at the lowest point of a vertical circle for looping the loop is √(5gr), where r is the radius of the circle. b) Derive an expression for centripetal acceleration of an object in uniform circular motion in a plane. What will be the direction of the velocity and acceleration at any instant? OR a)What is angle of banking? Obtain an expression for the maximum possible speed of a car on a banked road. Hence discuss the motion of the car on a level road. b) Discuss the motion of a car on a circular level road. 30. a)State the two angles of projection for which the horizontal range is the same. Prove that the sum of the maximum heights for these two angles does not depend upon the angle of projection. b) The maximum range of projectile is 2/√3 times its actual range. What is the angle of projection for the actual range OR a)Prove that there are two times for which the projectile travels the same vertical distance. Also prove that the sum of the two times is equal to the total time of flight. b)Two balls are thrown with the same initial velocity at angles α and (900-α) with the horizontal. What will be the ratio of the maximum heights attained by them?