How far did the man walk and what was his average speed?

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Homework Help Overview

The problem involves a man walking two segments of a journey, with specific distances and angles given in polar coordinates. The discussion focuses on calculating total distance, displacement, average speed, and average velocity over the trip duration.

Discussion Character

  • Exploratory, Assumption checking, Mathematical reasoning

Approaches and Questions Raised

  • Participants discuss the total distance traveled and question the relationship between distance and displacement. There is an exploration of how to calculate displacement using vector components and trigonometric functions.

Discussion Status

Some participants have provided confirmations of calculations, while others express confusion regarding displacement and seek examples. There is an acknowledgment of the need to consider vector quantities for velocity calculations, indicating a productive exploration of the topic.

Contextual Notes

Participants note the distinction between scalar and vector quantities, and there is mention of potential grading implications for minor calculation errors. The discussion reflects uncertainty in applying trigonometric principles to the problem setup.

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Homework Statement



A man walked 440 m 50 degrees polar positive, and then 580 m 185 degrees polar positive. The entire trip took 150 min.

Total distance travelled?
The displacement of the man?
Average of the man in m/min?
Average velocity of the man in m/min?

Homework Equations



Speed=Total Distance/Total Time
Average velocity=Displacement/Total Time

The Attempt at a Solution



I graphed this out. I was accustomed to distance being N/S/W/E. Distance is a scalar quantity so it doesn't really into account positive and negative.

Would my total distance traveled be 1020 m?

Help please?

c. 1020 m/150 mins=6.8 m/s
 
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a. Correct. The man walked 440m then 580m so he walked a total of 1020m.
b. However at the end of his walk he is not 1020m from his starting point. So how far is he?
c. You are correct.
d. Velocity is a vector quantity. We need the sum of his two velocity vectors. Or more simply the displacement from question b divided by the total time.
 
I'm confused as how to calculate displacement for this, can you give me an example please?
 
C would actually be 6.8m/min...just a small mistake but you might lose marks :P
 
To calculate the displacement you can make a triangle and have the hypotenus be his distance, then you can do 440 sin 50 degrees as his first displacement, and then I believe you would add to that 580 sin 185 degrees (which would be a negative number)...I believe his total displacement would be 286.5 m...I'm not positive though.
 

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