Answers to the Fluids review questions

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Fluid characteristics and Flow Rate Review Questions

1.  What are fluids? Give three examples of fluids.

Fluids are: substances that can flow, they have no definite shape and they can be both gases and liquids. Their particles are must more spread out than a solid. They take the shape of their container. Examples: Water, oil, air.

2.  Solids cannot flow. Explain using the particle theory why this statement is true.

Particles in a solid are too tightly packed together; therefore, there is very little space between them which does not allow them to flow. They do not take the shape of their container.

3.  What is flow rate? How might the flow rate of a fluid be affected?

Flow rate: Measures the volume of fluid moving past a certain point in a given amount of time.

Flow rate can be affected by:

}  Type of fluid (thin fluids flow faster than thick ones)

}  The force pushing the fluid (stronger the force = faster the fluid)

}  Size of the opening the fluid flows through (larger opening = faster flow)

}  Type of surface the fluid is flowing on (smooth surfaces = faster flow)

4.  Squeezing a mustard container results in 60ml of mustard coming out in 5 seconds. Calculate the flow rate of the mustard. Show all your work.

60/5 = 12 Therefore the flow rate is 12ml/s

5.  How might viscosity affect a fluid’s flow rate?

By increasing the viscosity or “thickness” of a fluid, it slows down the flow rate because the particles are closer together and therefore unable to flow as easily. Viscosity increases a resistance to flow.

6.  How might warming a substance with high viscosity, such as honey, increase the flow rate? Use the particle theory to help explain your answer.

By warming a substance, such as honey, it allows for the particles to create more space between themselves and “thins” out the fluid. This process allows the fluids to flow at a faster rate.

  

7.  Pouring honey into a container results in 560 ml of honey coming out in 35 seconds. Calculate the flow rate of the honey. Show all of your work.

560/35 = 16

Therefore the flow rate of honey is 16ml/s

8.  What are the differences between laminar flow and turbulent flow? Provide examples for each.

Laminar Flow – Smooth and regular (water flowing from the tap)

Turbulent Flow – Choppy and irregular (waves in an ocean)

9.  How might a change in temperature (e.g., from warm to cold or from cold to warm) affect the flow rate of a fluid? Explain using the particle theory.

Increasing the temperature allows for the particles to spread apart and reduce the viscosity (therefore, decreasing the resistance of flow)

Decreasing the temperature allows for the particles to grow closer together increasing the viscosity (therefore, increasing the resistance to flow)

10.            Why are fluids considered “essential to life”? Justify your answer.

Fluids are essential to life because we require them in order to perform the functions of our bodies. Without fluids we cannot breathe, blood cannot flow and our cells, tissues and organs would not be able to function.