# Solve the following :

Question:

The given figure shows the graph of $x$-coordinate of a particle going along the $X$-axis as a function of time.

Find

(a) The average velocity during 0 to $10 \mathrm{~s}$

(b) Instantaneous velocity at $2,5,8$ and $12 \mathrm{~s}$.

Solution:

(a) Velocity=displacement/time

$=\frac{100}{10}=10 \mathrm{~m} / \mathrm{s}$

(b) Instantaneous velocity=slope of v-t graph

At t=2.5s; slope = $=\frac{100-50}{10.7 .5}=20 \mathrm{~m} / \mathrm{s}$

At t=12s; slope $=$

$\frac{0-100}{15-10}=-20 \mathrm{~m} / \mathrm{s}$