Kinematics Numerical 3( A car starts from rest )
Kinematics Numerical 3: A car starts from rest. Its velocity becomes 20 ms in 8 s. Find its acceleration.
Solution:
A car starts from rest …
Rate of change in velocity is called acceleration(i-e change in velocity w.r.t time is called acceleration) . Here the initial velocity of the car is zero because car was at rest initially! The final velocity of the car is 20 meters per second.
Let;s arrange the given data as under;
Initial velocity =Vi= 0 m/sec
Final velocity=Vf=20 m/sec
Time =t= 8 sec
Acceleration=a=?
We get change in velocity as
\[ \triangle V=Vf-Vi=20-0=20 \frac{m}{sec} \]
We divide this change in velocity on time taken to get the rate of change of velocity — or simply to get the acceleration !
i-e
\[ a=\frac{\triangle V}{t}=\frac{20}{8}=2.5\frac{m}{sec^2} \]
So , the acceleration is 2.5 meters per second square
