IB physics past paper help

[DarkChestofWonders]

Can someone with access to the May 2008 paper help?( It's available in xtremepapers)

I can't seem to make sense of the answers to question B4 pt. 2 (Linear and circular motion) Can someone please explain it to me?

[Sofia.]

Can you take a photo and upload it, so that we don't have to download the paper?

[DarkChestofWonders]

Sure.

The biggest problem I have in this question is the dots. The mark scheme tells us to draw two dots, when I only found space for one. Also, why is the final speed 2.4 and not 2.2? Finally, distance at 5.6s given by the mark scheme seems to be the distance at 4.8s. 

[ibprincess]

(A) 

(i) distance between dots is increasing indicating the car is accelerating

(ii) from the first dot, the second dot is 7 units away, between the 2nd and 3rd dot there are 9 units and between the 3rd and 4th there are 11. assuming the car is accelerating at a constant rate, the distance between each pair of dots is increasing (or decreasing) by 2 units so from the first dot, go back 7-2 units (5 units), then 5-2 units (3 units) then 3-2 units (1 unit)

(iii) if a dot is made every 0.8s then count the dots forward (including the 3 drawn ones) until you reach 5.6s (8 dots forward). then, if every 1cm = 4m and every 1cm=1 big box on the grid, measure the distance from t=0s to t=5.6s which is 9.6cm=~37.5m

 

(B)

(i) between the final 2 dots is 2.2c=8.8m

v=s/t

v=8.8/0.8 

v=11ms^-1

(ii)A=v-u/t where u=0 because it started from rest so

A=v/t

A=2/0.8

A=2.5ms^-2

 

 

 

I hope this made some sense???