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Question
A car driver going at some speed v suddenly finds a wide wall at a distance r. Should he apply brakes or turn the car in a circle of radius r to avoid hitting the wall?
Solution
- When breaks applied-
v2 = u2 + 2aS
(0)2 = (v)2 + 2 × (-a) × r
a = `(v^2)/(2r)` ...(i)
- When the car takes a turn -
ac = `(v^2)/r` ...(ii)
On comparing (i) and (ii)
abreak = `(a_c)/2`
= Driver should apply breaks.
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