Chapter 13: Fluids

Question 1

what is density?

Answer 1

density can be thought of as mass per unit volume, the units are kg/m^3
ρ = m / V

Question 2

what is meant by ‘specific gravity’?

Answer 2

specific gravity is a ratio of the density of a substance to the density of water which is useful in the study of fluids (density of the object / density of the fluid)
SG = ρ(o) / ρ(f)

Question 3

what is pressure?

Answer 3

pressure is force per unit area, it is a scalar (not a vector), SI units are N/m^2
P = F / A = ρgh

Question 4

calculating force due to water pressure?

Answer 4

y = 0 at the surface level
determine the y0 and yf values for the area of interest, integrate the area with respect to depth (dy) times ρg(other variables involved with area including y)

Question 5

SI value of pressure of the atmosphere at sea level?

Answer 5

1.013x10^5 N/m^2

Question 6

how do you get absolute pressure?

Answer 6

gauge pressure + atmospheric pressure = absolute pressure

Question 7

archimedes principle

Answer 7

the buoyant force on an object immersed in a fluid is equal to the weight of the fluid displaced by that object (volume of the solid replaced by water ‘weight’)

Question 8

Formula for buoyant force

Answer 8

F(B) = (weight of object) - (weight of the volume of water displaced by the object)
F(B) = (mg) - (ρ(w) * V * g)

Question 9

density of water

Answer 9

1x10^3 kg/m^3

Question 10

equation of