Professional Application (a) A 5.00-kg squid initially at rest ejects 0.250-kg of fluid with a velocity of 10.0 m/s. What is the recoil velocity of the squid if the ejection is done in 0.100 s and there is a 5.00-N frictional force opposing the squid’s movement. (b) How much energy is lost to work done against friction?
Step-by-step solution In this problem we have to calculate the recoil velocity against the frictional force and the loss in energy Step 1 of 6 (a) Initially squid does not have any velocity. So, the initial momentum of squid be zero. Here the final mass of the squid is: There is a frictional force; then, there will be an interference of the force. So, momentum will not be conserved. Now, the expression of impulse in terms of force is, Here, is frictional force and is time space in which the force acts. Step 2 of 6 Therefore in this case the expression of change in momentum (impulse) is, Here, is mass of the fluid, is final mass of the squid, is velocity of the fluid and is recoil velocity of squid. Step 3 of 6 Combine the expression of impulse and change in momentum is, Substitute, for , for , for , for and for , So, the recoil velocity is ; away from the fluid ejected.