Electromagnetism Exercise

[PostMortem]

http://www.teiath.gr/userfiles/s.ath...im_2011_12.pdf

I have some trouble in exercise 1 and 2.

Exercise 1 says: There is a load q=-1μC in point A in axis x that is 0.15m form point O on the start of the axis. In the same time a second load Q is in point B of the axis Z that is 0.10m from point O on the start of the axis. The loads q and Q are moving with speeds u1 and u2. The direction of the two speed is shown on the graph, while we know that |u1|=10^7 m/s and |u2|=5*10^7 m/s. If the magnectic field on the point O is equal with zero calculate: a) The value and the sign for the load Q
and b) The electric field on point O


Exercise 2 says: Three loads Q1=-1nC, Q2=+2nC and Q3 are on axis x an specifically Q1 on the start of the axis, Q2 on the point X=0.1m and Q3 on the point X=0.3m

The loads Q1 an Q2 are moving with speeds u1 and u2, while the load Q3 is not moving. |u1|=|u2|=10^8 m/s.
If the total electric force that is being wielded on load Q1 equals zero calculate:
A) The value and the sign for load Q3
B)The magnetic force on load Q1.

[Hero999]

The link doesn't work.

What do you want us to do about it?

[PostMortem]

http://www.teiath.gr/userfiles/s.athinaios/documents/trapeza_thematwn/2011_12_xeim/hlektromagnitismos_a_xeim_2011_12.pdf

[Hero999]

What parts of the questions are you struggling with?

Have you attempted them yourself?

[PostMortem]

All of it. Of course i attempted to solve them but there are not similar exercises in my notes so i don't know how to solve them. I'm not looking for someone to solve them for me just maybe some formulas i can use or any help at all.