Conceptual Questions|| physics chapter 3 || class 11 physics || force and motion || Hindi/Urdu|

Choose the best possible answer 1. A ball is thrown vertically upwards at 19.6 m/s. For its complete trip (up and back down to the starting position), its average speed is:: A. 19.6 m/s B. 9.8 m/s C. 6.5 m/s D. 4.9 m/s 2. If you throw a ball downward, then its acceleration immediately after leaving your hand, assuming no air resistance, is A. 9.8 m/s2 B. more than 9.8 m/s2 C. less than 9.8 m/s2 D. Speed of throw is required for answer 3. The time rate of change of momentum gives A. Force B. Impulse C. Acceleration D. Power 4. The area between the velocity-time graph is numerically equal to: A. Velocity B. Displacement C. Acceleration D. Time 5. If the slope of velocity-time graph gradually decreases, then the body is said to be moving with: A. Positive acceleration B. Negative acceleration C. Uniform velocity D. ZERO acceleration 6. A 7.0 kg bowling ball experiences a net force of 5.0 N. What will be its acceleration? A. 35 m/s2 B. 7.0 m/s2 C. 5.0 m/s2 D. 0.71 m/s2 7. SI unit of impulse is: A. kg ms−2 B. N s C. N s−1 D. N m 8. A ball with original momentum +4.0 kg ×m/s hits a wall and bounces straight back without losing any kinetic energy. The change in momentum of the ball is: A. + 4 N s B. - 4 N s C. + 8 N s 2 D. - 8 N s 9. A body is traveling with a constant acceleration of 10 m s-2. If S1 is the distance traveled in 1st second and S2 is the distance traveled in 2nd second, which of the following shows a correct relation between S1 and S2? A. S1 = S2 B. S1 = 3S2 C. S2 = 3S1 D. 2S2 = 3S1 10. During projectile motion, the horizontal component of velocity: A. Changes with time B. Becomes zero C. Remains constant D. Increases with time 11. A projectile is thrown horizontally from a 490m high cliff with a velocity of 100 ms-1. The time taken by projectile to reach the ground is A. 2.5 s B. 5.0 s C. 7.5 s D. 10 s 12. A projectile is launched at 45o to the horizontal with an initial kinetic energy E. Assuming air resistance to be negligible what will be the kinetic energy of the projectile when it reaches its highest point? A. 0.50 E B. 0.71 E C. 0.70 E D. E 13. To improve the jumping record the long jumper should jump at an angle of A. 30o B. 45o C. 60o D. 90o 14. Range of a projectile on a horizontal plane is same for the following pair of angles: A.15o and 18o B. 43o and 47o C. 20o and 80o D. 52o and 62o Give a short response to the following questions 1. If you are riding on a train that speeds past another train moving in the same direction on an adjacent track, it appears that the other train is moving backward. Why? 2. Can the velocity of a body reverse the direction when acceleration is constant? If you think so, give an example. 3. When you stand still on the ground, how large a force does the ground exert on you? Why doesn’t this force make you rise up into the air? 4. A man standing on the top of a tower throws a ball vertically up with certain velocity. He also throws another ball vertically down with the same speed. Neglecting air resistance, which ball will hit the ground with higher speed? 5. The cricket coach explains that the follow-through with the shot will make the ball travel a greater distance. Explain the reasoning in terms of the impulse-momentum theorem. 6. When you release an inflated but untied balloon, why does it fly across the room? 7. Modern cars are not rigid but are designed to have ‘crumple zones’ (irregular fold) that collapse upon impact. What is the advantage of this new design? 8. Why we can hit a long sixer in a cricket match rather than if we toss a ball for ourselves? 9. An Aeroplane while travelling horizontally, dropped a bomb when it was exactly above the target, the bomb missed the target. Explain. 10. Calculate the angle of projection for which kinetic energy at the summit is equal to one-fourth of its kinetic energy at point of projection. 11. For any specific velocity of projection, the maximum range is equal to four times of the corresponding height. Discuss. 12. What is the angle for which the maximum height reached and corresponding range are equal? #feelnature #education #1styear #class11 #physics #11thphysics #balochistanboard #kpkboard #fscpart1