Question

The average time taken by a normal person to react to an emergency in one-
fifteenth of a second called the reaction time. If a bus is moving with a velocity of
60km/h and its driver sees a child running across the road, how much distance
would the bus have moved before he could apply the brakes? The reaction time
of people increases when they are intoxicated. How much distance had the bus
moved if the reaction time of the driver were 1/2 s under the influence of alcohol?

Answer 1

Answer:

Bus is moving with initial velocity of u = 60 km/hr.

60 km/hr = ( 60 X 1000)/3600 = u = 16.66 ms-1.

Reaction time = t =1/15 sec.

Distance would the bus had moved before pressing the bus would be = u X t.

S = 16.66 X 1/15 = 1.1 m.

Now if the driver is intoxiacated then reaction time would be t = 1/2 seconds.

So S becomes S = u X t = 16.66 X 1/2 = 8.33m.