Straight line motion problems with kinematics

[man0005]

Homework Statement

The questions and my answers are all on the attachment below
s

Homework Equations

The Attempt at a Solution

 

[DJsTeLF]

The thumbnails are barely legible. Please transcribe the specific questions for which you need help and your attempts at answering them.

 

[verty]

Man005, perhaps you could start by explaining your thought process for question 10.

 

[man0005]

um if you could check 9 and then through from 12-19 would be good
7 should be B
8 should be A
and 9 should be C
forgot to check that

um for 10? just made a triangle and found hypotenuse?

 

[DJsTeLF]

7 should be B
8 should be A
and 9 should be C

agreeded for 7 and 8, think again about 9..

hint - if you deduct a vector, it's the same as adding one of the opposite direction

 

[man0005]

hmm i did the same thing as the others (use the parallelogram method) and i got c
cant see what I've done wrong :S unless the 2 affects the method in some way