[PHYSICS PROB] Squids rely on jet propulsion to move around. A 1.5 kg squid
drifting at 0.40 m/s suddenly expels 0.10 kg of water backward
to quickly get itself moving forward at 2.5 m/s. If drag is ignored
over the small interval of time needed to expel the water (the
impulse approximation), with what speed relative to itself does
the squid eject the water?

Question

chupacabraj · Answer

Conservation of momentum?

agent0smith · Answer

Yes. Magnitude of 
change in momentum of water = change in momentum of squid

agent0smith · Answer

$$\Large m_{water} \Delta v_{water} = m_{squid} \Delta v_{squid}$$

chupacabraj · Answer

oh so 

.10(v-.40)=1.5(2.5-.40)
.
.
.
v= 31.9 m/s

agent0smith · Answer

Actually since it says relative to itself, so i think you can ignore the initial 0.4m/s for the water

agent0smith · Answer

.10(v)=1.5(2.5-.40)

chupacabraj · Answer

thanks