Question

. A ball is thrown vertically upwards from the ground. It crosses a point at the height of 25 m twice at an

interval of 4 secs. The ball was thrown with the velocity of

(A) 20m/sec. (B) 25 m/sec. (C) 30m/sec. (D) 35 m/sec.​

Answer 1

Answer:

Explanation:

the initial velocity the ball was thrown up is 29.566 m/s to cross the 25 m point twice at an interval of 4s.  After reaching the maximum height , it falls for 2seconds to reach the 25 m height. Distance it has fallen is h = 0.5 gt^2 = 0.5*10* 4 =20 m. Maximum height is 25+20 = 45 m.