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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) ) ? |
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Answer» Solution :Here, H = 20 m, 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 2THETA)/g =((40)^(2) xx sin 120^(@))/10` `=((40)^(3) xx 0.866)/10 = 138.56` cm |
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