How did they get J? I figured out how to get I

Question

amtran_bus · Answer

attachment

asnaseer · Answer

HINT:$$2.18\times10^5=218\times10^3$$

amtran_bus · Answer

Right. But do I multiply the big fraction up front by everything or just the part where the J is?

asnaseer · Answer

also:$$1.8\times10^4=18\times10^3$$both of these were then converted from N to kN as:$$1kN=10^3N$$

amtran_bus · Answer

Thanks! Do I multiply the big fraction up front by everything or just the part where the J is?

asnaseer · Answer

not sure what you mean by that?

amtran_bus · Answer

See, this is an example to a different one I am working. My question is how did they get-218 J from that long equation?

asnaseer · Answer

Oh I see what you are asking now.

Yes, they distributed the big outer fraction into each of the terms inside the brackets

amtran_bus · Answer

Even the ones associated with I?

asnaseer · Answer

who wrote this out? was it you or is this someone else's working?

amtran_bus · Answer

Webassign.com tutorial

asnaseer · Answer

I am talking about the hand written part

amtran_bus · Answer

Webassign.com tutorial

asnaseer · Answer

there may be a mistake in the braketing

amtran_bus · Answer

I took a screenshot

asnaseer · Answer

from the working out it looks like what was calculated was something along the lines of:$$a[(b-c)i-dj]=a(b-c)i-adj$$

asnaseer · Answer

because the final value against the j terms looks like it was multiplied by the outer fraction. So my guess is that whoever hand wrote the answer didn't put the brackets in the right place.

amtran_bus · Answer

Ohhhhh ok. Thanks! I like the way you laid it out.

asnaseer · Answer

np and yw :)