Question

Salmon often jump waterfalls to reach their

breeding grounds.
Starting downstream, 2.08 m away from a
waterfall 0.63 m in height, at what minimum
speed must a salmon jumping at an angle of
44 ◦
leave the water to continue upstream?
The acceleration due to gravity is 9.81 m/s
2
.
Answer in units of m/

Answer 1

5.45 m/s

Step-by-step explanation:

Given:

Δx = 2.08 m

v₀ₓ = v₀ cos 44°

aₓ = 0 m/s²

Δx = v₀ₓ t + ½ aₓ t²

2.08 m = (v₀ cos 44°) t + ½ (0 m/s²) t²

2.89 = v₀ t

Given:

Δy = 0.63 m

v₀ᵧ = v₀ sin 44°

aᵧ = -9.81 m/s²

Δy = v₀ᵧ t + ½ aᵧ t²

0.63 m = (v₀ sin 44°) t + ½ (-9.81 m/s²) t²

0.63 = 0.695 v₀ t − 4.905 t²

0.63 = 0.695 (2.89) − 4.905 t²

t = 0.530

v₀ = 5.45 m/s