Question

A 0.90 kg squid initially at rest ejects 0.30 kg

water vertically downwards with speed ,v = 20.0

m/s from siphons which are some parts of its body

to swim upwards. By using conservation of

momentum, find the speed of the squid after

ejecting the water. Ignore any resistance occured.

Answer 1

The speed of the squid is

$$u=mv/M=0.3·20/0.9=6.67\text{ m/s}.$$