Question

a body starts from rest. If it travels with an acceleration of 2 m/s², its displacement at the end of 3 seconds is?​

Answer 1

Answer:9m

Explanation:

Using Newton's 2nd equation of motion :

s =ut+ $\frac{1}{2}$a$t^{2}$

s= (0)t +$\frac{1}{2}$2$3^{2}$

s= $\frac{1}{2}$×2×9

s= 9

Displacement at the end of 3 sec = 9 m

Answer 2

Explanation:

Given:

Body starts from rest. So, initial velocity $=0 m/s$

Constant acceleration $=2m/s^{2}$

Time duration for motion $=3 s$

To find: Displacement of the body

Calculation:

When a body moves with uniform acceleration or when the acceleration is constant, then kinematics equations are used for determining the parameters of motion.

Consider a body to be in motion with initial velocity of $u$ and final velocity of $v$. Let the value of uniform acceleration be $a$ and displacement of body be $s$ for time duration of $t$.

From kinematics equation:

1. $v=u+at$

2. $s=ut+\frac{1}{2} at^{2}$

3. $v^{2} =u^{2} +2as$

Now, $s=ut+\frac{1}{2} at^{2}$ can be used for calculating displacement.

$s=0*3+\frac{1}{2} *2*3^{2} \\s=9m$

So, displacement is $9m$.

Answer:

Displacement is $9m$ at the end of $3s$ time duration.