Question

an object moves from a to b with speed of 20m/s and returns from b to a speed of 40m/s the average velocity of object the whole journey was​

Answer 1

Answer:

30

Explanation:

I mean that's as simple as it gets! welcome to the world of average( except if you look at the 2 trips seprate

Answer 2

Answer:

The average velocity of object is 26.67 m/s.

Explanation:

Given,

an object moves from a to b with speed of 20m/s.

So speed in first case is $20$m/s.

Again the object r returns from b to a speed of 40m/s .

So speed in second case is $40$m/s.

Here we want find average velocity of the object.

We know average velocity =$\frac{2xy}{x + y}$

Where x is speed in first case and y is speed in second [Remember this is applicable, if in both cases distance is same]

In this question the object first covers distance between a and b.Again at the return time that object covers the same distance.

So here x=20 m/s and y=40 m/s

So average velocity of the object$= \frac{2 \times 20 \times 40}{20 + 40} = \frac{2 \times 20 \times 40}{60} = \frac{80}{3} = 26.67$m/s.

One more important formula of speed and distance chapter,

Distance $= \frac{Time}{Speed}$