# Homework Help: Projectile Motion (No initial velocity)

1. Sep 13, 2008

### th7172

1. The problem statement, all variables and given/known data
A salmon starts 2.00 m from a waterfall that is 0.55 m tall and jumps at an angle of 32.0. What must be the salmon's minimum initial speed to reach the waterfall.

2. Relevant equations
$$\Delta$$y=visin$$\Theta$$$$\Delta$$t+1/2g$$\Delta$$t2

3. The attempt at a solution
I have tried all the related formulas for projectile motion, and I felt like I got somewhere a few times. But the results aren't really checking with a graphing calculator.
1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

2. Sep 14, 2008

### danago

Try to write expressions for the vertical and horizontal displacement at any given time (in terms of the unknown initial speed, ofcourse).

For some particular value of time, the vertical displacement will be 0.55m, and at the same time, the horizontal displacement will be 2m. You can use this information to find v.