Question

How do find a unit vector?

Answer 1

Divide the vector by its magnitude

Answer 2

At time 0.2 sec after is has been hit by a tennis racket, a tennis ball is located at (5,7,2)m relative to an origin in one corner of a tennis court. At a time 0.7 sec after being hit, the ball is located at (9,2,8)m.

Answer 3

What vector would you use?

Answer 4

let a vector be =xi+yj+zk
then \[\left| A \right|\] would be its magnitude and would be equal to \[\sqrt{x^{2}+y^{2}+z^{2}}\]
hence unit vector would be /\[\left| A \right|\]=xi+yj+zk/[\sqrt{x^{2}+y^{2}+z^{2}}\]

Answer 5

That made no sense to me... :/

Answer 6

What is i, j, k?

Answer 7

I know the average velocity and the average speed..would i just divide those by each other?

Answer 8

i, j, and k are the unit vectors in the x, y, and z directions. The following two notations are equivalent:
\[ <a,b,c> = a\vec{i} + b\vec{j} + c\vec{k} \]

Answer 9

If you have some vector <a,b,c>, then you can make it a unit vector by dividing by its magnitude:

\[ \left< \frac{a}{\sqrt{a^2+b^2+c^2}}, \frac{b}{\sqrt{a^2+b^2+c^2}}, \frac{c}{\sqrt{a^2+b^2+c^2}} \right> \]

Answer 10

You start out at <5,7,2> and end up at <9,2,8>. If you subtract the first from the second, you find that the vector pointing from the first to the second is <9-5,2-7,8-2> = <4,-5,6>. So, in the above example, a would be 4, b would be -5, and c would be 6. I believe your question wants you to find the unit vector pointing along this direction, so divide by the magnitude as shown above.