Question

The position-time graphs above represent the motions of cars $1$ to $5$.
How do they rank, according to their speeds (greatest first)?

• A. $1,2,3,4,5$
• B. $1,2,3$ and $5$ tie $4$
• C. $1,2,4,3$ and $5$ tie
• D. $3$ and $5$ tie, $4,2,1$
• E. $5,4,3,2,1$

Answer 1

The correct option is C $1,2,4,3$ and $5$ tie

The slope of position-time graph gives us the speed of the object at that point.

From the given graph, we see that the slope of cars $3$ and $5$ is zero. Hence, their speed is zero. Also, the slope of cars in decreasing order is given as $1,2,4$.

Hence, the correct rank according to their speeds is $1,2,4,3$ and $5$ tie