Question

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

Answer 1

Do you have a displacement over time graph

Answer 2

okay

Answer 3

Physics suck, I feel ya big time

Answer 4

\[V_{avg} = \frac{ \Delta x }{ \Delta t }\]

Answer 5

In words: the average velocity is equal to the displacement (change in x) over the change in time.

Answer 6

So I assume that 4km East means he traveled 4km East from an origin point. What do you think you should do first?

Answer 7

Subtract? idk lol

Answer 8

Well, not exactly. We want to convert our units. Velocity is in meters per second. Right now we have kilometers and minutes. We need to convert our displacement and time to the proper units.

Answer 9

1 km = 1000 meters
1 minute = 60 seconds.

Answer 10

Do you know how to do that?

Answer 11

No

Answer 12

\[\frac{ 4 km }{ 1 } \times \frac{ 1000 m }{ 1 km }\]

Answer 13

You multiply the conversion rate by the number you want to convert.

Answer 14

ok

Answer 15

so 4000?

Answer 16

of what?

Answer 17

km

Answer 18

Look at what I posted, what happens when you multiply across?

Answer 19

oh m

Answer 20

yes, it becomes:
\[\frac{ 4000 m \times km }{ km }\]

km/km = 1

the km's cancel out

Answer 21

Have you identified the change in time?

Answer 22

Yes

Answer 23

What is that?

Answer 24

Minutes

Answer 25

The change in time is how long it took for the hiker to traverse a given displacement.

Answer 26

idk whats happening honestly

Answer 27

ok

Answer 28

Look at Part A. What time did the hiker start at?

Answer 29

9:00

Answer 30

What time did he end at?

Answer 31

9:45

Answer 32

So how much time passed?

Answer 33

45 minutes

Answer 34

See, pretty simple, that is the change in time

Answer 35

oh

Answer 36

The graph is basically saying, it took him 45minutes to travel 4km East.

Answer 37

oh ok

Answer 38

So we have already converted 4km to 4000m. Do you think you can convert 45minutes to seconds?

Remember, 1 minute = 60 seconds.

Answer 39

2700

Answer 40

Can you show me how you set that up?

Answer 41

45*60

Answer 42

\[\frac{ 45 minutes }{ 1} \times \frac{ 60 seconds }{ 1 minute }\]

This is the form you should aspire to use. Some conversions get pretty tricky so try to think of it this way.

(Number you want to convert) times (Conversion Rate).

Answer 43

ok

Answer 44

So what is our change in time

Answer 45

2700 seconds

Answer 46

What do we do next?

Answer 47

divide?

Answer 48

Yes, we use:
\[V_{avg} = \frac{ \Delta x }{ \Delta t}\]

Answer 49

Let me know what you get

Answer 50

ok

Answer 51

88.888

Answer 52

i feel like thats wrong

Answer 53

What numbers did you use

Answer 54

45 and 4000

Answer 55

Velocity is in m/s, what is 45 of?

Answer 56

wait i was supposed to do 2700/4000?

Answer 57

It is displacement (change in x) over change in time.

Answer 58

4000/2700

Answer 59

correct, do that and remember your units

Answer 60

1.48 m/s

Answer 61

Correct. Just two things...

1. That is fine if your teacher wants you to round to the second decimal point. If he/she has said different, then adjust accordingly.
2. You're missing something vital...something specific to velocity and displacement (big hint).

Answer 62

What is it

Answer 63

Try and figure it out. Another hint is to look at the data in the picture.

Answer 64

East?

Answer 65

Correct

Answer 66

Displacement and velocity is different from speed and distance because they have direction, because they are vectors. Therefore if you must give it direction.

Answer 67

If you leave it at 1.45m/s it's just speed, not velocity.

Answer 68

Oh ok, thank you so much for your time

Answer 69

No problem

Answer 70

Glad I could help.