जॉइन Examsbookउत्तर : 3. "30 m/s"
A ball is thrown vertically upward from the ground. It crosses a point at the height of 25 m twice at an interval of 4 seconds. The ball was thrown with the velocity of5
प्र: A ball is thrown vertically upward from the ground. It crosses a point at the height of 25 m twice at an interval of 4 seconds. The ball was thrown with the velocity of
- 118 m/sfalse
- 225 m/sfalse
- 330 m/strue
- 436 m/sfalse
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उत्तर : 3. "30 m/s"
व्याख्या :
Answer: C) 30 m/s Explanation: The interval between object pass the same point is 4 sec. That means in 2 sec, object reaches the top and in next 2 sec, it again reaches the same point. By the info given, we can find the velocity of that point by using : v=u+(-gt) 0= u - 10×2 u = 20 Then the velocity at 25m is 20m/sec. so the initial velocity is -v2 = u2 + (-2gh)400 = u2 - 2x 10 x 25u2 = 900 => u = 30 m/s