Question

A body starts from rest from the origin with an acceleration of $6m/s^2$ along the X -axis and $8m/s^2$ along the Y - axis its distance from the origin after $4$ seconds will be

• A. $56m$
• B. $64m$
• C. $80m$
• D. $128m$

Answer 1

Answer: (C)

$80m$

Given,

$a_x=6m/s^2$

$a_y=8m/s^2$

$\overrightarrow{a}=a_x\hat{i}+a_y\hat{j}=(6\hat{i}+8\hat{j})m/s^2$

$a=\sqrt{6^2+8^2}=10m/s^2$

$t=4sec$

$u=0m/s$

From 2nd equation of motion,

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

$S=0\times 4+\frac{1}{2}\times 10\times 4\times 4$

$S=0+80=80m$

The correct option is C.