Starting from 1.73 m from a waterfall 0.55 m in height, at what minimum speed must a salmon jumping at an angle of 32◦ leave the water to continue upstream?

Question

Show work and this has to do with projectiles(just find the speed to continue upstream

Answer 1

There may be more than one way to work this problem. Here is the approach that comes to mind:

The trajectory from the jumping point to the top of the waterfall must follow a parabola given by

y(x) = (tanθ)x - [g / (2v²cos²θ)]x²

Assuming the salmon starts at point (0,0), it reaches the top of the waterfall at point (1.73, 0.55).

Plug these numbers into the equation for y(x) and solve for v:

x = 1.73 m

y = 0.55 m

θ = 32°

g = 9.8 m/s²

You will get an equation that you can solve for v. Try it.