Solution to problems - class 9 - Set 1 Q 19

Problem Statement

A car traveling at 20 m/s skids to a stop in 3 s. Determine the skidding distance of the car (assume uniform acceleration).

U = 20 m/s

V = 0

t = 3 s

Now S = ?

We will use, V² = U² – 2 a S
As V is zero, the equation becomes U² = 2 a S

S = U² / 2 a………(1)
we have to find out the value of a to solve this eqn.

To get the value of a, we will use this eqn V = U – a t.
As V =0,
so a = U/t = 20/3 m/s²….(2)

Now putting the value of a from equation 2 to equation 1,
we get S = 20² / [2 * (20/3) ] = 30 m