Question

Can anyone help me.. ?? I'm getting confused..please​

Answer 1

Answer: More than 19.6 m/s

Explanation:

Answer 2

Answer:More than 19.6m/s

Explanation:For at least 3 balls to remain above the ground, the time of flight of the first ball must be more than or equal to 4 s. Because in t = 4 s the third ball leaves the ground

So, -u = u – gt

=> u = gt/2

=> u = 9.8 × 4/2

=> u = 19.6 m/s

Thus, the ball must be thrown at speed more than or equal to 19.6 m/s