Question

A particle started moving from $P$ towards $S$ with uniform acceleration along a straight line. The average velocity of the particle from $P$ to intermediate point $Q$ is $8m/s$ and that $Q$ to $S$ is $12m/s$. If $QS=PQ$, then the average velocity from $P$ to $S$ is:

• A. $9.6$ $m/s$
• B. $12.87$ $m/s$
• C. $64$ $m/s$
• D. $327$ $m/s$

Answer 1

The correct option is A $9.6$ $m/s$

$8=\frac{x}{t_1},12=\frac{x}{t_2}$
$\overline{v}=\frac{2x}{t_1+t_2}$
$=\frac{2x}{\frac{x}{8}+\frac{x}{12}}$
$=\frac{2\times 8\times 12}{12+8}$
$=9.6m/s$