Question

If a body travels a distance of $97.52\text{m}$ along a straight line in $2.54\text{s}$, then its speed in appropriate significant figures is

• A. $38.4\text{m/s}$
• B. $38.3937\text{m/s}$
• C. $38.394\text{m/s}$
• D. $38.39\text{m/s}$

Answer 1

The correct option is A $38.4\text{m/s}$

We know that, the speed of a body is given by,
$v=\frac{d}{t}$, where $d$ is distance travelled and $t$ is time taken.
$\Rightarrow v=\frac{97.52}{2.54}=38.3937\text{m/s}$
We know that in multiplication or division, the final answer should have as many significant figures as in given data with minimum number of significant figures.
Here, $2.54\text{s}$ have the minimum number of significant figures equal to three. Therefore, the final answer should have three significant figures.
On rounding off $38.3937\text{m/s}$ to three significant figures, we get, $38.4\text{m/s}$.