MBOSE XI 2018 PYQ

10. A body is projected horizontally from a height of 10 m, with a speed of 9.8 m/s. After what time of its projection, will the horizontal and vertical components of velocities be equal? [1] 11. A ball is thrown upwards with a velocity of 100 m/s. How much time will it take to reach the ground? (Take g = 10 m/s²) [1] 13. Find the effective length of a second's pendulum. [1] 29. Two ball bearings each of mass 'm' moving in opposite directions with equal velocities v collide head on with each other. Predict the outcome of the collision, assuming it is perfectly elastic. [3]