An object is released from rest from a building, it takes 2s to reach the mid-point of the building. Find the further time needed for the object to fall to the ground.
A. 0.83s
B. 1.33s
C. 2.00s
D. 2.83s
The answer provided is A.
Please show working, thanks a lot!! :)
CE level Physics MC
2008-04-16 7:10 am
回答 (1)
2008-04-16 7:31 am
✔ 最佳答案
s = ut + (0.5)at^2s = 0.5 x 10 x 4
s = 20
becoz mid-pt is 20m , so the total height of the building is 40m
s = ut + (0.5)at^2
40 = 0.5 x 10 x t^2
t^2 = 8
t = 2.828427
so the extra time from its mid-pt is 2.828427 - 2 = 0.83
參考: me
收錄日期: 2021-04-13 15:26:36
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