Question

An object moves in a straight line along $x$-axis, its distance from the origin is given by $x = 10t^2\, m$. The average velocity in the time interval from $t_1 = 2\, s$ to $t_2 = 3 \,s$ is

• A. $50 \,m s^{-1}$
• B. $25 \,m s^{-1}$
• C. $20 \,m s^{-1}$
• D. $5 \,m s^{-1}$

Answer 1

Answer: (A)

$x=10 t^{2}$
average velocity $=\frac{x(t 2)-x(t 1)}{t 2-t 1}$
av.vel. $=\frac{90-40}{3-2}$
$=50 \,m\,sec ^{-1}$