Applied Maths Mechanics (AS M1)

[Ancient]

Hi everybody.
I have started with the M1 Mechanics Course this term and my teacher gave me some exam questions to do over the half term break but now I am stuck on one of the questions and I hope someone here will be able to help me.

So here is the question:
(read l as lamda and m as mue)

A force F2 = (l i + m j ) acts on a particle.

Show that 2l - m + 1 = 0.
Given that the direction of F2 is parallel to j

I have started to think about this problem and came up with

(l + m) = (0+1) x constant
l = 0 x constant.
m = 1 x constant.

But this does not really help me at all. and i can't think about much else to do so I am very happy over every hint you can offer me.

Thanks in advance.
Ancient.

 

[HallsofIvy]

Perhaps I don't understand the question. If F2 is li+ mj, is there an F1?
"Given that the direction of F2 is parallel to j" it follows that l must be 0. It is NOT necessary that m= 1. Is there another force with i component 1- m?

 

[Ancient]

Hi and thanks for helping.

There is another Force F1 = (2i + 3j) but I do not think that it is relevant for this part of the question.