Physics Question

Question

A flying squid (family Ommastrephidae) is able to "jump" off the surface of the sea by taking water into its body cavity and then ejecting the water vertically downward. A 0.94-kg squid is able to eject 0.32 kg of water with a speed of 20 m/s.(a) What will be the speed of the squid immediately after ejecting the water?

 m/s

(b) How high in the air will the squid rise?

? m

Answer 1

A 0.94-kg squid is able to eject 0.32 kg of water with a speed of 20 m/s.(a) What will be the speed of the squid immediately after ejecting the water?

 m/s

Alyssa H.

According to the law of conservation of momentum,

Total momentum of a system (during an interaction) is zero.

so (immediately following the ejection) momentum of water ejected + the momentum of the squid = 0

{0.32kg x 20m/s} + {0.94kg x Vm/s} = 0

0.94•V kgm/s = - {6.4kgm/s}

V m/s = - { 6.4kgm/s/0.94kg}

V = - 6.8 m/s (negative sign indicates that the water and squid are moving in opposite directions.

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Mr. A (Frank)