Question

1. Swordfish are capable of stunning output power for short bursts. A 650 kg swordfish has a cross-sectional area of 0.92 m2 and a drag coefficient of 0.0091- very low due to some evolutionary adaptations. Such a fish can sustain a speed of 30 m/s for a few seconds. Assume seawater has a density of 1026 kg/m3. a) How much power does the fish need to put out for motion at this high speed

Answer 1

Answer:

$P_{sp}=178.4W/kg$

Explanation:

From the question we are told that:

Mass of fish $m_f=650kg$

Cross-sectional area $A=0.92 m^2$

Drag coefficient of $\mu= 0.0091$

Seawater  density $\rho= 1026 kg/m^3.$

Speed of  Fish $v=30 m/s$  

Generally the equation for Drag force F_d is mathematically given by

$F_d = \mu * \rho *A v^2 /2$

$F_d = 0.0091* 0.92* 1026* 30^2/2 \\F_d= 3865. 35 N$  

Generally the equation for high speed  Power  $P_{sp}$ is mathematically given by

$P_{sp}=3865*35*\frac{v}{m_f}$

$P_{sp}=F_d*35*\frac{30}{650}$

$P_{sp}=178.4W/kg$