Chapter 4.2

Question 1

What is the definition of hydrostatics

Answer 1

• it is the study of fluids at rest

- >also the pressures and forces associated with standing fluids

Question 2

What is Pascal’s principle

Answer 2

• for fluids that are incompressible
• > a change in pressure will be transmitted undiminished to every portion of the fluid/ walls of the vessel containing the fluid

Question 3

Describe how hydraulic systems work. Note there is conservation of energy in this system

Answer 3

• they generate a force output
• > by magnifying an input force by a factor equal to the ratio of the Larger cross sectional piston to that of the Smaller cross sectional piston
• essentially apply a small force over a small area over a large distance
• > and you get a larger force over a larger area over a smaller distance

Question 4

What is Archimedes principle? What concept does it deal with? How can you describe it in terms of volume displaced?

Answer 4

• it deals with buoyancy
• > how objects stays afloat
• note buoyant force is always upwards
• > liquid tries to return to the space from which it was displaced
• states that a body immersed in fluid will be buoyed upwards by a force equal to the weight of the fluid that it displaces
• any object placed in a fluid will cause the fluid to be displaced equal to the volume of the object that is submerged

Question 5

Describe an object sinking or floating from the point of the Archimedes principle

Answer 5

object will sink

• > if volume of displaced fluid does not exert buoyant force equal to the weight of the object
• > the object will accelerate downward
• > in this case the object is more dense than the fluid it is in

objects will float
->when an object is less dense than water

Question 6

What is surface tension? What is it a result of

Answer 6

• it causes the liquid to form a thin but strong layer at the liquid’s surface
• > it is a result of cohesion
• on the surface
• > water molecules have strong attractive forces from molecules below
• > pulls the surface of the liquid towards the center

Question 7

When does a meniscus form and when does a backwards meniscus form

Answer 7

Meniscus forms
->adhesion is greater than cohesion

Backwards meniscus
->cohesion is greater than adhesion