In this question after vertical and horizontal velocities were calculated while calculating total time of vertical motion. sir . you have taken -15 as the total distance covered. in the ques we have been asked about the total time for motion to reach the ground. so i think that first max height should be calculated. then this max height should be added to 15. and then this resultant quantity should be place at the position while calculating time in the quadratic eq. this would give the total time when the ball was in motion before it hits the ground. OR we could also calculate time of flight separately and then add it to the 3sec that u have calculated for the dist. of 15m. this would give the same result.
8 months ago