This is a question from a book that I'm reading to learn Physics:
Quote:When the sun is directly overhead, a hawk dives toward the ground with a constant velocity of 5.00 m/s at 60.0 degrees below the horizontal. Calculate the speed of the hawks shadow on the level ground.
Here is what I think the graph looks like:
|
_____|________________
|\
| \ @ = 60.0
| \
|
I know that the speed is the magnitude of the vector, but my problem is finding the vector components or maybe there is another vector that I should be calculating. I know that the vector components are:
Vx = V cos(@)
Vy = V sin(@)
Would this mean that:
Vx = 2.5 m/s
Vy = -4.330127019 m/s
I wanted to make sure that Vx and Vy are correct so I did:
tan @ = Vy/Vx which equals the angle the hawk is fling in, so I know the V components are correct.
One guess I thought was that the shadow would be moving at the speed of the Vx because its moving across the x axis, but I belive that is wrong although the answer the book says is 2.5 m/s. I just doesn't seem like that would be all I have to do to solve the problem.
If I take the magnitude of V which is the speed:
|V| = sqrt(Vx^2 + Vy^2) = 5
And that doesn't seem right. I'm thinking that I'm not going in the right direction with this problem. Am I missing something or not using an Equation or something. What do you think?
Thanks you for all relpies,
- LostSource
[Edited by - LostSource on June 8, 2006 8:53:21 PM]
