yrelhan4
The driver of a car moving on a straight road applies brakes to come to rest, with a constant retardation 'a'. Assuming that the time of motion is more than 2 s, the distance covered by the car in secondlast second of its motion is
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Distance Travelled in nth Second
\[Dn = u + \frac{ a }{ 2 }[2n-1]\]
Since the Question Talks about retardation
\[Dn = u - \frac{ a }{ 2 }[2n-1]\]
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\[v = u -at\]
\[u = at\]
t - 1 = n
t = n +1
u = a (n+1)
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Nw Substitute the Value of u in the 1st equation
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\[Dn = an + a - an + a/2 = 3a/2\]
yrelhan4
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Thank you! (:
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Welcome...
yrelhan4
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why is t-1=n?
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secondlast second of its motion
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let t be the total time
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secondlast = t-1
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oh.. haha.. ty again!