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A car is moving at 72kmph. Brakes are su...

A car is moving at `72kmph`. Brakes are suddenly applied causing all the tyres to skid. How far will the car move before coming to a stop (given `g=9.8ms^(-2)` and `mu=0.2`)?

Text Solution

Verified by Experts

`u=72kmphxx(5)/(18)` `u=20ms^(-1)`
`F_(k)=mu mg=0.2xx9.8m=1.96m`
But `F=F_(k)`
i.e. `m(-a)=1.96m`
`:.a=-(1.96//m)m` `a=-1.96ms^(-2)`
Applying `v^(2)=v_(0)^(2)+2as` we get
`0=(20)^(2)+(2)(-19.6)s`
`s=((400)/(3.92))m`
`:.s=102.0m`
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