A body goes from A to B with a velocity of 20 m/s and comes back B to ...
If we presume that the distance is x m, then in the first case, the time needed is x/20 s.
In the second case the time is x/30
The total distance covered is 2x m
The total time
=(x/20+x/30) s
=5x/60 s
=x/12 s
Now, the average velocity will be
=total distance / total time
=2x/(x/12)m/s
=24 m/s
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A body goes from A to B with a velocity of 20 m/s and comes back B to ...
Average velocity is defined as the total displacement divided by the total time taken. In this case, the body goes from point A to point B with a velocity of 20 m/s and then returns from point B to point A with a velocity of 30 m/s.
To calculate the average velocity, we need to find the total displacement and the total time taken.
- Finding the total displacement:
When the body goes from A to B, the displacement is the distance between A and B, which we can call d1.
When the body comes back from B to A, the displacement is the distance between B and A, which we can call d2.
Since the body returns to its original position, d2 is equal to d1 but in the opposite direction. Therefore, d2 is equal to -d1.
The total displacement is the sum of d1 and -d1, which is equal to 0.
- Finding the total time taken:
Let's assume the time taken to go from A to B is t1, and the time taken to come back from B to A is t2.
The total time taken is the sum of t1 and t2.
Now, let's calculate the average velocity using the formula:
Average velocity = Total displacement / Total time taken
Since the total displacement is 0, and any number divided by 0 is undefined, we can conclude that the average velocity of the body during the whole journey is 0.
Therefore, the correct answer is option 'A' - 0 m/s.
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