The ceiling of a long hall is 20 m high. What is the maximum horizontal distance that a ball thrown with a speed of 40 ms^(-1) can go without hitting the ceiling of the hall (g = 10 ms^(-2)) ?

The ceiling of a long hall is 20 m high. What is the maximum horizonta

1.	The ceiling of a long hall is 20 m high. What is the maximum horizontal distance that a ball thrown with a speed of 40 ms^(-1) can go without hitting the ceiling of the hall (g = 10 ms^(-2)) ?
Answer» Solution :Here, `H = 20M, u = 40 MS^(-1)`. Suppose the ball is thrown at an angle `THETA` with the horizontal. Now, `H = (u^(2) sin^(2) theta)/(2g) rArr 20 = ((40)^(2) sin^(2) theta)/(2 xx 10)` or, `sin theta = 0.5 ""` or, `theta = 30^(@)` Now `R = (u^(2) sin 2 theta)/(g) = ((40)^(2) xx sin 120^(@))/(10)` `= ((40)^(2) xx 0.866)/(10) = 138.56 CM`