Help... P6 problem?

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a driver of a bus moving 90 km/hr suddenly sees a beggar crossing 40 m ahead. it takes 0.8s for the driver to apply the brakes. if the maximum acceleration during braking is 11m/s^2 the beggar hit by the bus? pls show your solution.. tnx

2007-07-09 22:25:25 · 2 answers · asked by help_me7 1 in Science & Mathematics ➔ Physics

2 answers

the beggar was not hit by he because.... it only takes 16 m....

2007-07-11 23:08:24 · answer #1 · answered by ewan_jrj777 2 · 0⤊ 0⤋

The bus is travelling at 90/3.6 = 25 m/s.

In the first 0.8 seconds the bus travels (25)(0.8) = 20 m. During braking it will travel a distance s given by v^2 = u^2 + 2as => 0 = 25^2 + 2(-11)s => s = 28.4 m. So the bus will need a total of 48.4 m to brake - so the beggar will be hit.

2007-07-10 05:32:07 · answer #2 · answered by Scarlet Manuka 7 · 0⤊ 0⤋