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Units density and specific gravity
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Units density and specific gravity
Units density and specific gravity
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1
Question
What is the SI base unit for time and its symbol?
Answer
Second, symbol s
2
Question
What is the SI unit for force in terms of base units?
Answer
Newton (N) = kg·m/s²
3
Question
What is the SI prefix for 10³ and its symbol?
Answer
Kilo, symbol k
4
Question
What is the SI prefix for 10^-3 and its symbol?
Answer
milli, symbol m
5
Question
What is the SI prefix for 10^0 and its symbol?
Answer
none; 10^0 is the base unit (no prefix)
6
Question
What is the relationship between weight W, mass m, and gravity g?
Answer
W = mg
7
Question
What is the standard acceleration due to gravity at sea level?
Answer
9.81 m/s^2
8
Question
Which balance scales are shown in the mass measurement image?
Answer
Ancient Mass Balance Scale and Digital Mass Balance
9
Question
What is mean sea level (MSL) used for in geography?
Answer
Baseline for elevations and depths
10
Question
What does the left image of a 1 kg mass indicate about weight at sea level?
Answer
W = 9.81 N (approximately)
11
Question
What is the weight on the Moon relative to Earth for a 100 kg mass according to the example?
Answer
16.6 kgf (approx) on Moon; 100 kgf on Earth
12
Question
What is g (acceleration due to gravity) at sea level as given in the material?
Answer
g = 9.81 m/s^2
13
Question
What unit is defined as the weight per unit volume of a fluid?
Answer
Specific weight, γ (gamma)
14
Question
What is the formula for density?
Answer
density = mass/volume or ρ = m/V
15
Question
What is the relationship between specific volume and density?
Answer
Specific volume v is the reciprocal of density: v = 1/ρ
16
Question
What is the density of water in kg/m^3 as listed?
Answer
1000 kg/m^3
17
Question
What does SG stand for in material science, and what is it?
Answer
SG stands for Specific Gravity; it's the ratio ρ_s/ρ_w (dimensionless)
18
Question
What is the relationship between density and temperature for liquids and solids according to the text?
Answer
Density variation with pressure is negligible; mainly affected by temperature
19
Question
What is the unit of density in the provided content?
Answer
kg/m^3
20
Question
What is 1 kgf equivalent to in newtons as given?
Answer
1 kgf = 9.81 N
21
Question
What is the unit for specific volume and how is it defined?
Answer
m^3/kg, reciprocal of density (v = V/m)
22
Question
What does the specific weight γ represent?
Answer
Weight per unit volume of a fluid (γ = W/V = ρg)
23
Question
What is relative density (specific gravity) relative to at 4 °C water?
Answer
ρs/ρw ( SG = ρs/ρw )
24
Question
What is SG of a substance if its density equals that of water?
Answer
SG = 1
25
Question
Why do substances with SG < 1 float on water?
Answer
They are lighter than water (density less than water)
26
Question
How is SG for gases defined?
Answer
Ratio of gas density to air density (SG = ρg/ρa)
27
Question
What is the density of air at STP used for SG calculations?
Answer
ρa = 1.2754 kg/m^3 at 0 °C, 101,325 Pa
28
Question
What does SG > 1 imply about buoyancy in water?
Answer
Material sinks in water
29
Question
What does SG < 1 imply about buoyancy in water?
Answer
Material floats in water
30
Question
What is the relationship between specific gravity and mass-density definitions for solids and liquids?
Answer
SG = ρs/ρw = γs/γw (density or weight-based)