Question

3. A particle goes in a straight line from a point A to B with a speed 40kmph and
travels from B to A with a speed 60kmph. Calculate the average speed and average
velocity for the entire journey.​​​

Answer 1

Explanation:

Let the distance from A to B be = x

Therefore, the total journey = 2x

Time from A to B , T1 = x/40

Time from B to A , T2 = x/60

$average \: speed = \frac{2x}{t1 + t2}$

$= \frac{2x}{ \frac{x}{40} + \frac{x}{60}} = \frac{2}{ \frac{2 + 3}{120} } = \frac{2 \times 120}{5}$

$= 48 \: km {h}^{ - 1}$

Displacement = 0 ( as the initial and the final position are same )

$average \: velocity = \frac{displacement}{time}$

$= \frac{0}{time} = 0 \: km {h}^{ - 1}$

Therefore, it is your answer.

I hope it helps you. If you have any doubts, then don't hesitate to ask.