# physics multiplying vectors

posted by
**sam**
.

In the product F = qv · B , take q = 4,

= 2.0i + 4.0j + 6.0k and = 136i -176j + 72k.

What then is in unit-vector notation if Bx = By?

~~may i get some assistance in this problem? so far.. i tried this..

136i-176j+72k = 4(2.0i+4.0j+6.0k)(B)

136i-176j+72k = (8i+16j+24k)(B)

[(136i-176j+72k)/(8i+16j+24k)] = B

17i-11j+3k = B

thats wrong.. so should i be doing this?

136i-176j+72k = (8xi+16yj+24zk)(Bxi+Byj+Bzk)

136i-176j+72k = (8xBxi+16yByj+24zBzk)

???

i need some help asap, that would be great. thanks again!

Fill in the blanks in your question

<< In the product F = qv · B , take q = 4,

___= 2.0i + 4.0j + 6.0k and ___= 136i -176j + 72k.

What then is ___ in unit-vector notation if Bx = By>>

If the B vector is 2.0i + 4.0j + 6.0k, then Bx and By are NOT equal. Your question is incomplete and does not make sense.

You didn't multiply...

136i-176j+72k = (8i+16j+24k)(B)

But B= Bxi +Byj + Bzk

136i-176j+72k = (8i+16j+24k)(Bxi +Byj + Bzk)

136i-176j+72k= 8Bx k -8By j + 16Bx k +16Bz i + 24Bx j- 24By i

Now gather the terms, set the i terms equal to i, and so on. Check my work, I did it in my head.

sorry, the complete question is:

n the product F = qv · B , take q = 4,

v = 2.0i + 4.0j + 6.0k and F= 136i -176j + 72k.

What then is in unit-vector notation if Bx = By?

I still can't get the right answer though...