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# SUVAT equations in 2 dimensions

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1. Can it still use the equations, SUVAT, when considering motion in 2 dimensions.
Obviously we can still use but can we also still use
as you're squaring a vector which obviously you can't do?
In this case would you just square each of the components of the vector in the i, j (and k) directions and treat it like that instead?
2. (Original post by Ano9901whichone)
Can it still use the equations, SUVAT, when considering motion in 2 dimensions.
Obviously we can still use but can we also still use
as you're squaring a vector which obviously you can't do?
In this case would you just square each of the components of the vector in the i, j (and k) directions and treat it like that instead?
Provisionally, yes.

You need to treat the motion in the i,j (and k in 3D) directions separately.

Some will work as vector equations, as long as you're not "multiplying" two vectors together. So, v=u+at and s=ut+(1/2)at^2.

You could even define vector multiplication as being componentwise and then use the other equations as well - but this is to the best of my knowledge a non-standard usage/definition. I wouldn't recommend it for an exam.

Effectively you're just using the vector notation to represent two or three equations.

Note in , both "a" and "s" are vectors - a typo, I presume.
3. I suppose there isn't an absolute need to do it in vector form right?
I suppose you could right .
(Yes I meant to make s bold as well).
4. (Original post by Ano9901whichone)
I suppose there isn't an absolute need to do it in vector form right
I have seen markschemes use vectors for the equations where you don't have to multiply two vectors together.

I suppose you could right .
(Yes I meant to make s bold as well).
When refering to components (coordinates) of vectors, it's standard practice not to use bold. Just use bold for the vector itself, so:

, for example.
5. (Original post by ghostwalker)
I have seen markschemes use vectors for the equations where you don't have to multiply two vectors together.

When refering to components (coordinates) of vectors, it's standard practice not to use bold. Just use bold for the vector itself, so:

, for example.
I see.
If I may ask, what level of maths have you studied to? You seem very knowledgable in the subject.
6. (Original post by Ano9901whichone)
I see.
If I may ask, what level of maths have you studied to? You seem very knowledgable in the subject.
I can confirm what ghostwalker said; in fact, when you look deeper into such simple sounding problems, it's amazing how it remains fundamentally simple despite potentially being in a very complex scenario.
As for level, my experience says Uni level, but I wouldn't be surprised if some more advanced A-level mechanics topics delve into this
7. For v^2 = u^2 + 2as, replace multiplication with the dot product (v^2 is then the square of the magnitude of the vector v, same for u^2, and 'as' is the dot product of vectors a and s. This equation is just the work-energy principle (change in kinetic energy of body = work done on body).
8. (Original post by Ano9901whichone)
I see.
If I may ask, what level of maths have you studied to?
It's in my profile.

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