4.5.2. Mass Flow Rate and Thrust Calculation

Try these first

1. 1.

   What is the formula for mass flow rate?

   Hint

   Remember the relationship involving density, area, and velocity.

2. 2.

   What type of flow is assumed when density is constant?

   Hint

   Think about liquids and how their densities behave.

3. 3.

   What is the primary factor determining thrust in a fluid jet?

   • Density
   • Velocity
   • Volume
   • Pressure

   Hint

   Think about what happens to the mass flow as fluid speeds up.

4. 4.

   True or False: In incompressible flow, the speed of the fluid can change without affecting density.

   • True
   • False

   Hint

   Consider how liquids behave under pressure.

5. 5.

   A spacecraft is moving at 900 m/s, and a solid fuel engine expels gases at 70 kg/s. If the gases exit with a speed of 3000 m/s, calculate the thrust generated by the rocket engine.

   Hint

   Break down the components to calculate thrust correctly.

6. 6.

   If a water jet of 0.01 m² area strikes a plate at 25 m/s, and water density is 1000 kg/m³, determine the force applied to the plate due to the water jet.

   Hint

   Use mass flow rate to derive thrust.