A stone falling from the rest position. under the influence of gravity. it's strikes with a glass in time t loses half of it's velocity. if it then reached the ground in t seconds and gain velocity of 30m/s. find out time?

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Answer 1 · 2017-08-10T02:14:27

2 seconds

v = u + at
v = gt

Veocity when it strikes the glass = gt
It loses half of its velocity after striking the glass. Hence it now falls with velocity = #text(gt)/2#

Now....,
#v = u + at#

#30 = text(gt)/2 + text(gt)#

#30 = text(3gt)/2#

#t = 20/g#

If #g = 10ms^-2#

t = #2# seconds