Question

Observe the given distance-time graph.

Identify the respective speeds of the body when it moves from $O$ (Origin) to $A$ and $B$ to $C$.

• A. $2km{h}^{-1},4km{h}^{-1}$
• B. $1km{h}^{-1},3km{h}^{-1}$
• C. $3km{h}^{-1},5km{h}^{-1}$
• D. $4km{h}^{-1},6km{h}^{-1}$

Answer 1

The correct option is A

$2km{h}^{-1},4km{h}^{-1}$

When body moves from $O$ to $A$
Speed of body = Slope of $OA$
Here ($x_1,y_1$) = ($0.0$), ($x_2.y_2$) = ($1,2$)
$⟹Slope=\left(\frac{2-0}{1-0}\right)=2km{h}^{-1}$
Hence, speed of body is $2km{h}^{-1}$ when it moves from $O$ to $A$

When body moves from $B$ to $C$
Speed of body = Slope of $BC$
Here ($x_1,y_1$) = ($1.5,2$), ($x_2.y_2$) = ($2,4$)
$⟹Slope=\left(\frac{4-2}{2-1.5}\right)=4km{h}^{-1}$
Hence, speed of body is $4km{h}^{-1}$ when it moves from $B$ to $C$