• Support PF! Buy your school textbooks, materials and every day products via PF Here!

Time required for falling objects speed to double

  • Thread starter bigbobby
  • Start date
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.


Homework Helper
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?
Is it √(x^2 + y^2)

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

Thanks for your reply.


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

Physics Forums Values

We Value Quality
• Topics based on mainstream science
• Proper English grammar and spelling
We Value Civility
• Positive and compassionate attitudes
• Patience while debating
We Value Productivity
• Disciplined to remain on-topic
• Recognition of own weaknesses
• Solo and co-op problem solving