Vector Calc Easy Q: Solutions Here

[calculusisrad]

thanks

 

[SammyS]

Find c such thy v=I+2j-k and w=-I +5j +ck are perpendicular.

Is this right?
V * w = 0 (dot product)
So set the dot product equal to 0 and solve to get c = 9 ?

Or is it more complicated?

Thanks

That's the way to do it !

Also, a force of 50 lbs is directed 50 deg above horizontal, pointing right. Determine horizontal and vertical components and display results in a figure.

I used the pythagorean theorem to get horizontal= 50cos50 and so on for vertical. But I don't get how to draw the forces, the book shows them at weird angles but I thought they would just be drawn horizontally and vertically?

Thanks!

This is also correct.

 

[Deveno]

Find c such thy v=I+2j-k and w=-I +5j +ck are perpendicular.

Is this right?
V * w = 0 (dot product)
So set the dot product equal to 0 and solve to get c = 9 ?

Or is it more complicated?

Thanks

nope, that's exactly what you do.

Also, a force of 50 lbs is directed 50 deg above horizontal, pointin right. Determine horizontal and vertical components and display results in a figure.

I used the pythagorean theorem to get horizontal= 50cos50 and so on for vertical. But I don't get how to draw the forces, the book shows them at weird angles but I thought they would just be drawn horizontally and vertically?

Thanks!

i agree with you. i can't speak for what the book has drawn.