question_answer 21)

A ball is thrown vertically upwards with a velocity of 49 m/s. Calculate  (i) the maximum height to which it rises, (ii) the total time it takes to return to the surface of the earth.  

Answer:

Initial velocity, u = 49 m/s Acceleration, a = g = - 9.8 m/s2 Velocity at the highest point, v = 0 m/s (i) If h is the maximum height reached by the ball, then or   Thus, the ball will reach a height of 122.5 m. We have, Here, Total time