A ball is dropped from a height of ...
Question
A ball is dropped from a height of 20m and rebounds with a velocity which is 3/4th  of the velocity with which it hits the ground. What is the time interval between
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A ball is dropped from a height of ( 20 mathrm{m} ) and rebounds with a velocity which is ( 3 / 4^{text {th }} ) of the velocity with which it hits the ground. What is the time interval between the first and second bounces
( left(g=10 m / s^{2}right) )
(1) 3 sec
(2) 4 sec
(3) 5 sec
(4) 6 sec

NEET/Medical Exams
Physics
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A ball is dropped from a height of 20m and rebounds with a velocity which is 3/4th  of the velocity with which it hits the ground. What is the time interval between the first and second bounces (g=10m/s^2)
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If the boll is doopped from height h above the goound then it reaches the ground with speed.
[
V=sqrt{2 times 9 times h}
]
If it rebound with ( (3 / 9)^{text {th }} ) of the velocity then the taken t to reach maximum height after first bounce is given by
[
t=3 / 4 frac{sqrt{29} h}{9}=frac{3}{4} sqrt{frac{2 times h}{g}}=frac{3}{4} sqrt{frac{2 times 20}{10}}=frac{3}{2} mathrm{Se}
]
the ball will take sqmetime to reach the ground Just before 'second rebounce Hence the time interval between first and second rebounce is 3 seconds.

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