Question

A car is traveling at 20m/hr along a road side a child runs out into the road 50m ahead and the car driver steps on the brake speed what must the cars declarations be if the car is to stop just before it reaches the child

Answer 1

⇒ Speed of the car = 20 m / s

⇒ Distance of the child from the car when it goes into the road = 50m


TO FIND ;-

⇒  What must the car’s deceleration be if the car is to stop just before it reaches the child?


SOL ;-

⇒ Distance of the child from the car in the road ( S ) = 50 m

⇒ Initial velocity of the car ( u ) = 20 m / s

⇒Final velocity of the car ( v )   = 0 m / s



Now let us find the acceleration using the formula -


                           2 a s = v² - u ²

Here we need to find the acceleration so let us rearrange the formula ,


we get as -                            a = u² - v² / 2 as




                               ⇒  a = v² - u² / 2 s

                               ⇒  a = 0 - 20² / 2 × 50

                               ⇒  a = -  400 / 100 

                               ⇒ a =    -  4 m /s

                           So acceleration is - 4 m / s





HOPEFULLY ANSWERED !!!!!!!