A 5 kg stone falls from a height of 100m and penetrates 2m layer of sand.The time of penetration is:
i) 14.285 sec.
ii)0.089 sec.
iii)7.14 sec.
iv)0.89 sec.
Answers
Answered by
1
Answer:
the time of penetration is 0.89 second
Answered by
4
Answer:
(B)
Step-by-step explanation:
Speed of the stone just before touching the sand is is
v=√2gh=√2×9.81×1000=140.07m's
Declaration of the stone due to sand is
v²- u²=-2 as
0-140.07²=-2(a)(2)
a=4905m/s²
we have initial speed and the declaration, from
v=u-at
u=at
t=u÷a =140.07÷4905=0.0285s
So, the answer is 0.089sec.
HOPE IT HELPS YOU
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