d Find the retardation produced when a car

# Kinematics Numerical 4( Find the retardation produced when a car ..)

Kinematics Numerical 4: Find the retardation produced when a car moving at a velocity of 30 m/sec slows down uniformly to 15 m/sec in 5 sec.

Solution:

## Find the retardation produced when a car …

Here we see the change in velocity i-e acceleration is producing (being asked as retardation) which we will calculate.

We have the data;

Vi= 30 m/sec

Vf= 15 m/sec

t= 5 sec

We know the formula for acceleration ‘a’ ;

$a=\frac{Vf-Vi}{t}$

Putting values of variables;

$a=\frac{15-30}{5}=\frac{-15}{5}=-3 \frac{m}{sec^2}$

So, the acceleration is -3 m/sec^2 – being negative , it is  we call as ‘deceleration’

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