numerical based on relative density 5 question with answer.
Answers
Questions
Problem #1
An empty density bottle has a mass of 25 g. Its mass is 50 g when full of water & 45 g when full of another liquid. What is the relative... density of the liquid & what is it's density in kg/m^3?
Problem # 2
A solid ball has a mass of 100 grams and a radius of 2 cm. What is the density? (Answer: 2.98 g/cm3)
Problem # 3
A solid cylinder has a radius of 2 cm and a length of 7 cm. It has a density of 3.1 g/cm3. What is the mass of the cylinder? (Answer: 272.69 grams)
Problem # 4
Seawater contains approximately 3.5% salt by weight. How much seawater (in kg) contains 1 kg of salt? If the density of seawater is 1030 kg/m3, what is the volume of seawater, in liters, containing 1 kg of salt? (Answer: 28.57 kg, 27.74 L)
Problem # 5
A solid cylinder of length 10 cm is placed in water. It stands upright with the top 3 cm protruding above the water surface. The density of water is 1.0 g/cm3. What is the density of the cylinder?
Solutions
1) The relative density of any liquid or any other substance is given by the formula:
Relative Density=
(Mass of a given volume of the substance)/(Mass of a equal volume of water)
From the data given above we can calculate the mass of the liquid and water for volume equal to capacity of the density bottle as follows.
Mass of liquid = Mass of bottle full of bottle - Mass of empty bottle
= 45 - 25 = 20 g
Mass of water = Mass of bottle full of bottle - Mass of empty bottle
= 50 - 25 = 25 g
Therefore:
Relative density of liquid = (Mass of liquid)/(Mass of water)
= 20/25 = 0.8
Also:
Density in kg/m^3 = (Relative Density)*(Relative density)
We know density of water = 1000 kg/m^3
Substituting values of relative density and density of water in the above equation for Density, we get:
Relative density of liquid = 0.8*1000 = 800 kg/m^3