Practice Force Analysis (4.2) - Mass Conservation Equation - Fluid Mechanics - Vol 2

Practice: Force Analysis

Lesson 4.2Mass Conservation Equation

Practise this section

10 questions

Flashcard drill
4 cards from this section. Quick, good the night before a test.
Exercise
6 questions · about 4 min · pass mark 70%. Hints available.
Sign up to start the exercise
Quiz
4 questions · about 3 min · pass mark 70%. Hints available.
Sign up to start the quiz

6 sample questions

Question 1.
Define mass conservation in your own words.
Show hintHide hint
Consider what happens to mass in closed versus open systems.
Question 2.
What is incompressible flow?
Show hintHide hint
Think about how water behaves under normal conditions.
3Question 3.
What does the mass conservation principle state?
- Mass can be created
- Mass remains constant in a closed system
- Mass leaves the system
Show hintHide hint
Consider your understanding of closed versus open systems.
4Question 4.
Is incompressible flow characterized by constant density?
- True
- False
Show hintHide hint
Relate it to how water behaves under pressure.
Question 5.
Given a flat plate is moving at 10 m/s into a water jet with a velocity of 25 m/s, if the water density is 1000 kg/m^3 and the jet area is 0.05 m^2, calculate the net force exerted on the plate considering the jet splits equally.
Show hintHide hint
Use momentum equations involving relative velocities.
Question 6.
A spacecraft with a mass of 10000 kg is dropping towards Earth at a speed of 600 m/s. If it expels gas with a rate of 50 kg/s at a speed of 2000 m/s, calculate the thrust produced and how much force counteracts gravity (approximation 98000 N).
Show hintHide hint
Incorporate mass flow rate with exhaust velocity in your calculations.

6 more questions in this section. Enroll free to practise them all.