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Relative Velocity

Q.15 A lift p...

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Q.15 A lift performs the first part of its ascent with uniform acceleration a and the remaining with uniform retardation 2 a . If t is the time of ascent , find the depth of the shaft $(a) \frac{a t^{2}}{4} (b) \frac{a t^{2}}{3} (c) \frac{a t^{2}}{2} (d) \frac{a t^{2}}{8}$

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Solution

Dear Student ,
Here in this case from the given data we get that ,
$t_{1} = \frac{v}{a}, t_{2} = \frac{v}{2 a} a d d i n g t_{1} a n d t_{2} w e g e t t = \frac{3 v}{2 a} t = \frac{3}{2 a} \times \frac{2 h}{t} a t^{2} = 3 h, h = \frac{a t^{2}}{3}$
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