Time required for falling objects speed to double

[bigbobby]

An eagle is flying horizontally at 7.6 m/s with a fish in its claws. It accidentally drops the fish.
(a) How much time passes before the fish's speed doubles?
(b) How much additional time would be required for the fish's speed to double again?



Maybe someone else will understand this better than I am. There is no acceleration in the x direction, so they must be talking about the y direction. But if his initial y velocity was 0 (he is flying horizontally) then you can't double 0 ...



Thanks for any help.

 

[ideasrule]

No, the question is talking about the total speed, both vertical and horizontal. Do you know how to find total speed given vertical & horizontal speed?

 

[bigbobby]

Is it √(x^2 + y^2)

I'm still not quite sure how to find the vertical component though?

Thanks for your reply.

 

[ideasrule]

Yes. The vertical component is just gt, since gravity adds 9.8 m/s to the vertical speed every second.