Year 11 motion/vector problem?

  • Thread starter caitie_72
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Homework Statement


I'm really not good at motion. It just doesn't seem to come easily to me, which is kind of disapointing, because physics is my favourite subject.

Question: A body of mass 5kg is moving in a north easterly direction with a velocity of 28.3 m/s. If a westerly wind acts on it with a force of 73.5N what is the change in momentum after 8s.

Homework Equations


F = ma, a = v/s
???

The Attempt at a Solution


I figured i'd find the velocity of the force.
F = ma
73.5 = 5a
a= 14.7

a = v/t
v = 14.7 * 8
v = 117.6

difference in p = m(v-u)
p = 5(117.6-28.3)

But this doesn't give the right answer. The answer is 588 N s East.

I know i probably need to draw vectors and what not but the whole concept of vectors confuses me deeply. :(
Could you explain to me how the diagram would work? Would i need to use non-right trig? And also, what am i doing wrong?
I don't understand a lot of the concepts of vectors and motion, so try and explain it in the simplest way possible, because im not great at this stuff.

Any help is appreciated. Thanks :)
 

Answers and Replies

  • #2
Redbelly98
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You need to think about velocity components for this one.

The change in velocity is in the east/west direction. So what was the initial east/west velocity component?

p.s. welcome to PF.
 

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