A Chinook salmon has a maximum underwater speed of 3.0 m/s, and can jump out of

Question

A Chinook salmon has a maximum underwater speed of 3.0 m/s, and can jump out of the water vertically with a speed of 4.8 m/s. A record salmon has a length of 1.5 m and a mass of 61 kg. When swimming upward at constant speed, and neglecting buoyancy, the fish experiences three forces: an upward force F exerted by the tail fin, the downward drag force of the water, and the downward force of gravity. As the fish leaves the surface of the water, however, it experiences a net upward force causing it to accelerate from 3.0 m/s to 4.8 m/s. Assuming the drag force disappears as soon as the head of the fish breaks the surface and that F is exerted until two-thirds of the fish's length has left the water, determine the magnitude of F. N

Explanation / Answer

W = F d

d = 2/3 * 1.5 = 1.0 m

kinetic energy = 1/2 m * (v2 - u2)

F * 1 = 1/2 m * (v2 - u2) + m g

F/m = (1/2 * (4.82 - 32)) + 9.81

F/m = 16.83

F = 16.83 * 61

magnitude of force = 1027 N

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.