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A thief in stolen car passes through a p...

A thief in stolen car passes through a police check post at his top speed of `90kmh^(-1)` . A motorcycle cd reacting after 2s, accelerates from rest at `5ms^(-2)`. His top speed being 108km/h. Find the maximum separati between policemen and thief.

A

112.5m

B

115m

C

116.5m

D

None of these

Text Solution

Verified by Experts

The correct Answer is:
A
At maximum spearation their velocities are same
`:. " Velocity of car " =25m//s[90 km//hr=25m//s]`
or at `= 25 " or " t=5s :. a = 5 ms^(-2)`
But thief has travelled up to 7s
`s_1 = " displacement of thief " = v_1t_1 =25 xx 7 = 175m`
`s_2= " displacement of motorcycle cycle " =1/2 xxa_2t_2^2 = 1/2xx5xx(5)^2= 62.5m`
`:. " Maximum separation " =s_1 - s_2 = 112.5m`
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