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A driver can stop his car from the red s...

A driver can stop his car from the red signal at a distance of 20 m when he is driving at 36 kmph and 41.25 m when he is driving at 54 kmph. Find his reaction time.

Text Solution

Verified by Experts

Let t is reaction time of driver during which he moves with uniform speed
Distance coverd during reaction time =`S_(1)`=ut
As he applies brakes,distance covered before coming to rest is
`S_(2)=(u^(2))/(2a)`
Total distacne covered Is `S=ut+(u^(2))/(2a)`
`20=10t+(100)/(2a)`...........(1)
41.25=15t+`(225)/(2a)` ............(2)
Solving above equation 3.75 =7.5t
t=0.5s
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