The ball is thrown upward with the initial velocity of 42 meters per second from the cliff which is 90 meters high. Height of ball is provided by quadratic equation:
h= -4.9t2 + 42t +110 where h is in meters and t is time in seconds as ball was thrown. Determine time when ball will be 20 meters from ground.
i. 10.3 seconds
ii. 10.8 seconds
iii 10.7 seconds
iv. 10.4 seconds