Consider a vechicle moving with a velocity 54 km/h. At a distance of 400 m, from the trafic light brakes are applied.The acceleration of the vehicle, after the application of brakes is `-0.3 m//s ^(2).` The vehicle's position relative to the traffic light is

Options

A. 25m
B. 375m
C. 425m
D. 30m

Answer

A

Explanation

Given, initial velocity,
`u = 54 km//h = 54 xx (5)/(18) m//s u = 15 m//s`
Distance of signal from vehicle, `d = 400 m` acceleration,` a =- 0.3 m//s ^(2)`
Now, distance covered by vehicel, when it stops is given by `v ^(2) = u ^(2) + 2as`
`0= (15)^(2) -2 xx 0.3 xx s implies s = (225)/(0.6) = 375m`
Relative position `=400 - 375 =25 m`