Salmon often jump waterfalls to reach their breeding grounds. one salmon starts 2.00m from a waterfall that is 0.55m tall and jumps at an angle of 32.0 degrees. what must be the salmon's minimum speed to reach the waterfall?

6.2 m/s

Explanation:

1) This is a projectile motion (parabolic)

2) Velocity:

i) initial velocity = V₀

ii) Horizontal component:

V₀x = V₀ cos α

The horizontal velocity is constant, so Vx = V₀x

ii) Vertical component:

V₀y = V₀ sin α

The vertical component is linear with acceleration = g ≈ 9.8 m/s²

Vy = V₀y - gt = V₀ sin α - gt

3) Displacement equations

i) Horizontal displacment:

x = V₀ cosα t

ii) Vertical displacement:

y = V₀ sin α t - g t² / 2

y ≈ V₀ sin α t - 4.9 t²

4) Solution

i) x = V₀ cosα t = V₀ cos(32°) t = 2.00 m ← salmon starts 2.00m from a waterfall

⇒ V₀ = 2 / [cos(32°) t ]

ii) y = V₀ sin α t - 4.9 t² = V₀ sin(32°) t - 4.9 t²

iii) Replace V₀ with 2 / [cos(32°) t ]

y = sin(32°) × 2 / [cos(32°) t ] × t - 4.9t² = 2 tan(32°) - 4.9t²

iv) Use jump's height (y = 0.55m) and solve

⇒ 0.55 = 2 tan(32°) - 4.9t²

t² = [2 tan(32°) - 0.55 ] / 4.9 = 0.143 s²

⇒ t = √ (0.143s²) = 0.38 s

v) Use V₀ = 2 / [cos(32°) t ] to find V₀

V₀ = 2 / [cos(32°) (0.38) ] = 6.2 m/s

42

step-by-step explanation:

your answer is -9

step-by-step explanation: