A ball is initially placed at a position 1.6m above the ground.
The ball is projected upwards afterwards. It travels up to its maximum height and falls onto the ground in 3s. Neglecting air resistance, what is the initial vertical speed of the ball?
phys,,f.4
2008-10-14 5:58 am
回答 (1)
2008-10-14 7:23 am
✔ 最佳答案
Let the initial velocity be u and let upward is positivea = 9.81 m/s^2
use the formula, s = ut + 0.5at^2
-1.6 = u(3) + 0.5(-9.81)(3)^2
-1.6 = 3u - 44.145
u = 14.18m/s
2008-10-19 16:00:31 補充：
If the answer is B, the gravitational acceleration must be used 10m/s^2
-1.6 = u(3) + 0.5(-10)(3)^2
-1.6 = 3u - 45
43.4 = 3u
u = 14.47m/s = 14.5m/s
收錄日期: 2021-04-13 16:10:04
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