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 motion in straight line

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A cat runs along a straight line ( the x-axis ) from point A to point B to point C as showen in the figure. The distance between point A and C is 5m, the distance between point B and C is 10m and the positive axis is to right. The time to run from A to B is 20s, and from B to C is 8.00s. As the cat runs along the x-axis between point A and C 

1- what is the magnitude of its average velocity ? 

2- what is its average speed ? 

 Feb 16, 2015

Best Answer 

 #5
avatar+118613 
+5

Velocity has a magnitude and a direction.  The magnitude cannot be negative.

Hence I am sticking by my answer. 

 Feb 17, 2015

5+0 Answers

 #1
avatar+118613 
+5

Hi 315

 

Average speed is 15m/ 28 sec

 

Magnitude of

Average vel = 5m/28sec

 

I think that's right :)

 Feb 16, 2015
 #2
avatar+1832 
+5

very clear Thank you melody 

 Feb 16, 2015
 #3
avatar+118613 
+5

Well for speed he has traveled a total of 15m in 28 sec.

I know thats correct

now for velocity, direction counts. But you need magnitude so thats like absolute value.

well it  finishes 5m from the start point and it took 28sec to get there so the mag of the velocity is 5m/28sec.

I'm pretty sure that is correct ☺

 Feb 16, 2015
 #4
avatar+128707 
+5

Since velocity is a vector quantity the average velocity is just (-15 + 10) / 28  = (-5/28)m/s

Average speed is a scalar......it's just total distance/time = (15 + 10) /28m/s  = (25/28)m/s

I believe this is correct......

 

 Feb 16, 2015
 #5
avatar+118613 
+5
Best Answer

Velocity has a magnitude and a direction.  The magnitude cannot be negative.

Hence I am sticking by my answer. 

Melody Feb 17, 2015

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