squids are aquatic creatures that use jet propulsion for motion. Taking up water

Question

squids are aquatic creatures that use jet propulsion for motion. Taking up water in their main cavity they eject it out of a siphon which can be oriented in many different directions. A 20kg squid has a cavity that holds 68 mL of water. When the squid needs to move the cavity volume decreases by 40% and the expelled water allows the squid to attain a maximum velocity of 1.25 m/s. Assume that the squid shoots water out of its siphon at 6.7 g/s at a velocity of 3.8 m/s. What is the magnitude of the external force that would be required to keep the squid from accelerating?

Explanation / Answer

Thrust force , Ft = d p / dt = d ( m v) /dt = v dm/dt

dm/dt = 6.7 kg/s

Ft =6.7 x 3.8 = 25.46 N

Fnet = F + Ft - m g = 0

F = (20 x 9.8) - 25.46 = 170.54 N

Related Questions

Navigate

• Browse (All)
• Browse S
• Subjects

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