Hard Physics Question?

Question

what is your average velocity ifyou drive a distance of 174 km at a speed of 50 kn/h, then the same distance at a speed of 66 km/h? answer in unites of km/h

Answer 1

The first two answers are wrong. They are answering the question as if you drove the same amount of time at each speed, not the same distance at each speed.

To demonstate why this is wrong, use speeds of 1 km/h and 101 km/h. If you add 1 + 101 you get 102, and dividing by 2 you would get an average speed of 51 km/h. If your average speed was 51 km/h it would take you less than four hours to travel 172 km. But if you drove half that distance (87 km) at 1 km/h that would take 87 hours.

The total distance does not really matter, so you can simplify the problem a little by making the distance 132 km, 66 km at 50 km/h and 66 km at 66 km/h.

To drive 66 km at 50 km/h would take 66/50 = 1.32 hours.
To drive 66 km at 66 km/h would take 66/66 = 1 hour.
The total trip would take 2.32 hours to go 132 km.
That makes your average velocity 132 / 2.32 = 56.9 km/h.

Answer 2

I'm not sure, but I agree with Ira W who answer your question before I did. I just wanted to add how you might've solved it.

*To find an average, add up all numbers and divide by the total numbers present.

So apply that to this problem:
50 km/h + 66 km/h =116 km/h / 2 = 58 km/h

Answer 3

I am not sure if this is just a typing error, problem with syntax, or a trick question. VELOCITY is defined as rate of change of position, e.g. speed AND direction are needed. Speed on the other hand is a scalar (direction is irrelevant). So if this is exactly how the question was originally written, then there is not enough information given to answer. If the question had said it was towards the west, or any other direction it would be a velocity though.

Answer 4

58km/h