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M4 Collisions

Hello



In the above question, I'm not sure of two things.

The first is in part a). I understand the magnitude of the Impulse is 5m Ns, but I'm not sure why the direction is written as parallel to 0.2(-3i + 4j), and not simply parallel to (-3i + 4j). Are these directions not the same?

The second is in part b) and is more of a general difficulty I'm having with walls that are "tilted at angles" so to speak. I'm just not sure of the method in resolving components from vectors when we have walls that aren't parallel to either the i or j vectors.

I don't quite understand how the solution bank attempts to solve it. Would someone mind helping? :smile: Thank you very much
Reply 1
Avatar for TeeEm
TeeEm
19
Original post by Student403
Hello



In the above question, I'm not sure of two things.

The first is in part a). I understand the magnitude of the Impulse is 5m Ns, but I'm not sure why the direction is written as parallel to 0.2(-3i + 4j), and not simply parallel to (-3i + 4j). Are these directions not the same?

The second is in part b) and is more of a general difficulty I'm having with walls that are "tilted at angles" so to speak. I'm just not sure of the method in resolving components from vectors when we have walls that aren't parallel to either the i or j vectors.

I don't quite understand how the solution bank attempts to solve it. Would someone mind helping? :smile: Thank you very much


good question ...
I think I have similar but I will steal it anyway ... (tomorrow as I am very euphoric right now ...)
Reply 2
Avatar for Zacken
Zacken
22
Original post by Student403
Hello


Hello. :hi:

For part (a), it says parallel to the unit vector. Hence the 132+42\frac{1}{\sqrt{3^2 + 4^2}}.
Reply 3
Avatar for Student403
Student403
OP
19
Original post by TeeEm
good question ...
I think I have similar but I will steal it anyway ... (tomorrow as I am very euphoric right now ...)


euphoric? :eek:


Original post by Zacken
Hello. :hi:

For part (a), it says parallel to the unit vector. Hence the 132+42\frac{1}{\sqrt{3^2 + 4^2}}.


Oh thanks! Of course - silly me :facepalm:
Reply 4
Avatar for Zacken
Zacken
22
Original post by Student403

...


Okay, so I've never looked at M4 - what I'm saying might be utter crap. What the thing seems to be saying is that the resolved part of a vector a\mathbf{a} in the direction of another vector b\mathbf{b} is

(a.b∣b∣)b\displaystyle \left( \frac{ \mathbf{a} . \mathbf{b} }{|\mathbf{b}|}\right ) \mathbf{b}

which makes sense to me!

You're not going to like this... it's FP3 vectors. Look at Page 10 of your formula booklet.
(edited 8 years ago)
Reply 5
Avatar for Student403
Student403
OP
19
Original post by Zacken
Okay, so I've never looked at M4 - what I'm saying might be utter crap. What the thing seems to be saying is that the resolved part of a vector a\mathbf{a} in the direction of another vector b\mathbf{b} is

(a.b∣b∣)b\displaystyle \left( \frac{ \mathbf{a} . \mathbf{b} }{|b|}\right ) \mathbf{b}

which makes sense to me!

You're not going to like this... it's FP3 vectors. Look at Page 10 of your formula booklet.


Oh I see! That's very interesting/strange :lol:

@Duke Glacia could you let us know if Zacken's on to something?
Original post by Student403
Oh I see! That's very interesting/strange :lol:

@Duke Glacia could you let us know if Zacken's on to something?


dnt embarras me, Zakon in da room.

Spoiler

Reply 7
Avatar for Zacken
Zacken
22
Original post by Duke Glacia
substituting into the first eqn should give u what zacken wrote. and defo helpful at solving the questions.


:cool:
Original post by Zacken
:cool:


u dnt need M4 iz in ur blood

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