Question

An object starts rest at x=0 m and moves that constant acceleration of 2 ${2m/s}^2$ along the x axis .During journey from X=4 m to x=16 m, its average velocity is:

• A. 6 m/s
• B. 10 m/s
• C. 4 m/s
• D. 2 m/s

Answer 1

The correct option is A 6 m/s

Time taken in covering $x=4m$ will be given by $x=u+\frac{1}{2}a{t}^2$

initial velocity $u=0$ and acceleration $a=2m/s^2$so $t=\sqrt{\frac{2x}{a}}$

Thus on putting $x=4m$ we get time $t_4=2second$

Thus on putting $x=16m$ we get time $t_{16}=4second$

so the time interval is $t_{16}-t_4=2second$

and the distance is $16-4=12m$ so $V_{avg}=12m/2s=6m/s$