Question

The velocity of a body moving in a straight line at the end of $5\text{s}$ is $30\text{m/s}$, at the end of $12\text{s}$ is $58\text{m/s}$ and at the end of $22\text{s}$, it is $98\text{m/s}$. The body is moving with

• A. Uniform velocity
• B. Uniform acceleration
• C. Zero velocity
• D. Uniform retardation

Answer 1

The correct option is B Uniform acceleration

Let’s take the time interval b/w $5$ to $12\text{sec}$.
So: $u=30\text{m/s},v=58\text{m/s},t=12–5=7\text{s}$
So by first equation,
$v=u+at$
$58=30+7a$
$28=7a$
$a=4m/s^2$
Again let’s do the same for $12$ to $12\text{sec}$
So: $u=58\text{m/s},v=98\text{m/s},t=22–12=10\text{s}$
So by first equation,
$V=u+at$
$98=58+10a$
$40=10a$
$a=4m/s^2$
So the body is moving with uniform acceleration.