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https://i.gyazo.com/86224be9e2479f2276a24a4bdf193cc0.png 

https://i.gyazo.com/e163feb8a68d6a6e57748154ade6f874.png

 

questions on both links

 Feb 27, 2018
 #1
avatar+128473 
+2

I know a few

 

First one

 

The elevator is on the ground floor at  A  

 

The max upward velocity occurs at   B

 

 

Second one

 

C - 5 seconds

D - acceleration.....change in velocity / change in time  =

[ 18 m/s - 0 m/s ]  / 5sec =    (18/5)m/s^2 =  (3.6)m/s^2

 

E - Don't know this one

 

 F -  5 seconds

 

G -  acceleration  -  

[ 0 m/s - 18m/s ] / [14s - 18s ]  =  

-18m/s / [ -4sec] =  (-18/4)m/s^2  = -4.5m/s^2

 

H - don't know this one

 

I - don't know

 

cool cool cool

 Feb 27, 2018
 #2
avatar+36916 
0

E. Goes from 18 m/s to 0 m/s in 4 seconds    

Acceleration =  change in velocity / change in time

                       =  (0-18) / 4 = -4.5 m/s^2

 

H.  SImilar to E above   goes from  -18 m/s to 0/m/s in 5 seconds

 

0 -(-18) / 5 =  3.6 m/s^2

 Feb 27, 2018
 #3
avatar+36916 
0

I)

The area UNDER a velocity graph is the distance travelled....We need only look at the first triangle

1/2  b x h

1/2 x 9 s x 18 m/s= 81 meters high = 10th floor

 Feb 27, 2018
edited by Guest  Feb 27, 2018
 #4
avatar+128473 
0

Thanks, EP  !!!!

 

 

cool cool cool

CPhill  Feb 27, 2018

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