Confusing projectile motion question (1 Viewer)

[Bricnic]

This is from the Excel Fast Track "50 HSC Exam Tips- Maths Extension 1 (3 Unit)" book, by Pascall Press (written by Jeff Geha).

Page 119, or Tip 43: Projectile Motion- Moving targets and other applications.
Example 1:
A piece of bread is thrown to a bird at the top of a pole. However, at the instant the bread is thrown, the bird flies away in a horizontal straight line at a speed of 10 m/s. The piece of bread reachers double the height of the pole and, in its descent touches the bird. Find the horizontal component of the velocity of the piece of bread.

After all the working out etc. that has been done (which I will not include because there's a lot) an answer of 10(1+2^1/2)ms^-1 is found. The reason given half way through the working out is "Now, for the piece of bread to brush the bird, it must have travelled the same horizontal distance from the instance it was above the pole"

I find this to be quite confusing Just on observation, wouldn't both the bread and the bird need to have the exact same horizontal velocity to ever collide, i.e. 10ms^-1, if both travelling from the same original horizontal displacement (0) in the same direction?

 

[airie]

See diagram attatched.

The red line indicates the path of the bird, and as you can see this is the same as the horizontal distance travelled by the bread as it falls down from the maximum height. The bread was not thrown from the foot of the pole, but rather, a distance from it

 

[Bricnic]

Ah, so i see.. thanks a bunch