Question

What was the hiker's average velocity during part A of the hike?

http://static.k12.com/calms_media/media/1357500_1358000/1357620/1/185dd4e634bcb63a38595f220e8901f867258840/MS_PHYS_SCI_286559.jpg


A.
0.17 km/h north

B.
13.3 km/h west

C.
5.0 km/h north

D.
10 km/h north

Answer 1

Start with the fact that:
$$velocity_{avg} = v_{final} - v_{initial}$$

Answer 2

okay that doesn't help much I'm not good with equations

Answer 3

No problem, this problem can be explained with a picture too.

Answer 4

So let's break this problem down into parts.

At first, the hiker heads north. He travels 5km over 30 minutes. What is his velocity for this part?

Answer 5

5km I think

Answer 6

Velocity is your change in distance over change in time

Answer 7

oh the the 30 minutes

Answer 8

So $$velocity = \frac{change\ in\ distance}{change\ in\ time}$$

Answer 9

so \[v=\frac{ 30 }{ 5 }\]

Answer 10

Almost! You have $$v = \frac{30\ minutes}{5\ km}$$ you need $$v = \frac{5\ km}{30\ minutes}$$

Answer 11

Remember, velocity is you change in distance, divided by your change in time.

Answer 12

so I got 166666666666667

Answer 13

with . in front

Answer 14

Right, so he travels 0.167 km for every minute that he walks.

Answer 15

but there is not a option for that how do I put it in hours

Answer 16

Easy! If you travel 0.167 km in one minute, how many km do you travel in one hour?

Answer 17

wouldn't I do 0.167*6 or 60

Answer 18

Yes! 60. You are correct.

Answer 19

I got 10.02

Answer 20

For every minute of walking, you travel 0.167 km. If you walked for 60 minutes, you would have $$ 0.167\ km \cdot 60\ minutes = 10.02 km$$

Answer 21

BUT! That's not the average velocity. Let's continue.

Answer 22

You need to find his velocity for all 4 parts, north, west, south, and east.

Answer 23

no for only part A like the question says

Answer 24

Oh! I'm sorry. I misread the question. I thought it said find the average velocity for the whole trip.

Answer 25

So yes, for every 1 hour of walking, the hiker will travel 10.07 km. So his velocity is 10.07 km/hr