Question

A block is sliding down on an inclined plane. The velocity changes at a constant rate from $10cm{s}^{-1}$ to $15cm{s}^{-1}$ in $2$ seconds. What is its acceleration?

• A. $2.5cm{s}^{-2}$
• B. $1.5cm{s}^{-2}$
• C. $4.5cm{s}^{-2}$
• D. $1.25cm{s}^{-2}$

Answer 1

The correct option is A

$2.5cm{s}^{-2}$

The motion is depicted below

Let $u$ be the initial velocity, $v$ be the final velocity and $t$ be the time taken.

$v=15cm{s}^{-1},u=10cm{s}^{-1},t=2s$

We know that acceleration, $a$ is given by:

$a=\frac{v-u}{t}$

$a=\frac{15-10}{2}$ $cm{s}^{-2}$

$a=2.5cm{s}^{-2}$