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A ball thrown up vertically upwards reaches a certain height in 6 seconds. calculate the velocity with which it is thrown up, if g= 10m/s2 |
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Answer» A ball thrown up vertically upwards reaches a certain height in 6 seconds. We have to find the velocity of the ball with which ball is thrown up. From above data we have; height (h) is 6 m, final velocity (v) is 0 m/s [ at highest POINT, velocity = 0 ] and ACCELERATION due to gravity (a) is -10 m/s [ as it is against the motion ] First equation of motion: v = U + at Second equation of motion: s = UT + 1/2 at² Third equation of motion: v² - u² = 2as As we have value of v, a and s. So, using the Third Equation Of Motion i.e. v² - u² = 2as Substitute the known values in the above formula, → (0)² - u² = 2(-10)(6) → 0 - u² = -120 → u² = 120 → u = 10.95 → u = 11 (approx.) Therefore, the initial velocity of the ball is 11 m/s. |
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