Thread: Basic vectors help ...

I need to find the resultant vector c in magnitude and direction.

I found the magnitude to be 7.2 using cosine rule, i.e.:



However, I'm not able to find the magnitude.

So far, I have tried the following:

Since resultant vector c = a + b

ax = -(6 cos 40)
ay = 6

bx = 3 cos 70
by = 3

Then,
cx = ax + bx
cy = ay + by

But that doesn't seem to help.

Originally Posted by struck

I need to find the resultant vector c in magnitude and direction.

I found the magnitude to be 7.2 using cosine rule, i.e.: Unfortunately wrong



So far, I have tried the following:

Since resultant vector c = a + b Correct

...

I've modified your drawing a little bit.

I placed the origin at the beginning of vector . Using the indicated angle you'll get:

....... and .......

Now the next steps are quite easy.

I've got

Edit: errr.. never mind.

I actually got 7.6, but wrote 7.2 in my first post here.. So I was correct at least about that... Thanks