What is the minimum speed needed for a trout to jump a 2.5 m waterfall?

[whyorwhynot]

Kinematics Problem (Solved)

I greatly apologize for making this my very first post. I am in great need of assistance though, and I hope someone can help me comprehend how to solve this.
It seems relatively simple, but it does not seem to be clicking in my mind at the moment.

Homework Statement

A trout jumps a waterfall 2.5 m high. With what minimum speed did it leave the water below to reach the top?

Homework Equations

Issue at hand.

The Attempt at a Solution

I understand that Vf(final) = 0 m/s, x = 2.5 m, and Vo is what I am solving for.
I have a card of equations but I'm unsure as to which would apply to this. And I don't believe gravity plays a part in this, does it?

Thank you so much for your assistance.

 

[ak1948]

Gravity does play a part. In fact it would reach the top at any speed greater than zero if it weren't for gravity.

 

[whyorwhynot]

That makes much more sense then.
We've been using -9.8 m/s^2 in reference to falling objects though. Would this become +9.8 m/s^2 since the frog is jumping up, not down?

Thank you very much by the way!

 

[Mattowander]

No. Gravity is ALWAYS directed downward. If you defined up as the positive Y direction, then acceleration due to gravity is going to be negative.

Hope that helps :)

 

[whyorwhynot]

I understand it now. Thank you both so so much for your help!