Question

a car travelling on a level road at 72km/hr is stopped in 4sec by application of breaks .how much distance is travelled before stoping​

Answer 1

Answer:

40m

Explanation:

First, let's find the acceleration.

u = 72 km/h  = 72 * 5/18 = 20 m/s

v= 0

time = 4 sec

acceleration = v-u/ t

= 0-20/4

= -20/4 = -5 m/sec^2

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Now we know s = ut + 1/2at^2

So let us apply this formula to find the distance.

Distance = (20×4) + (1/2 × -5 × 16)

               = 80 + (-40)

               = 40m

∴ Total distance travelled before the car completely stopped = 40m