Vector math problem bugging me

[Don Nguyen]

I'll end up asking the professor tomorrow, but this bugged me all day!

To get the i component of the vector (before wind), I took:

475[SUP]2[/SUP]=a[SUP]2[/SUP]+80[SUP]2[/SUP] ==> a=(475[SUP]2[/SUP]-80[SUP]2[/SUP])[SUP]0.5[/SUP] ==> a=5(8769)[SUP]0.5[/SUP] ==> a=~468.21


Doing the similar operation for the wind vector, the i component was:

50(2)[SUP]2[/SUP]=~70.71.

So I add the two components together and get ~538.92. I even used this value to get the ground speed, which was right. I double checked and double checked again to make sure it worked and made sense. Am I making an incredibly elementary error here? I don't care about points but this bothers me to no end!

 

[gomipile]

Edit: never mind, forgot my definitions.

Hmmm.

Ok, here we go:

Your answer is off by .01 due to rounding. Carrying the calculation out gives 538.9253 to four decimal places, which rounds to 538.93, not to 538.92.

 

[darkaether]

heading east and pointing east are the same.

bearing east and going east are the same.

Which part is it saying is wrong?

 

[Don Nguyen]

Edit: never mind, forgot my definitions.

Hmmm.

Ok, here we go:

Your answer is off by .01 due to rounding. Carrying the calculation out gives 538.9253 to four decimal places, which rounds to 538.93, not to 538.92.

I guess I was reading into it wrong. I read "correct to 2 decimal places", and not rounding off, so I wasn't really thinking. Kinda wish this dumb program gave me the right answer when I answered wrong?