when 2.0 cm3 of a liquid vaporised, the volume of the
vapour is 2400cm3. what is the ratio of the density of the liquid
to density of the vapour? the answer's 1200. I don't find the
answer logically. anyone care to explain?
Density = Mass / Volume.
When the liquid is in liquid form, it has a mass, say M.
When it vapourise, its mass remain the same, still M.
Density of liquid = M / 2
Density of vapour = M / 2400
Ratio = (M / 2) / (M / 2400) = 1200
and a stel ball bearing of radius 5mm is of weight W. what is
the weight of a steel ball bearing of radius 10mm? the answer's
8W.
Volume of a sphere = 4/3 * pi * r^3
When the radius = 5mm, volume = 4/3 * pi * 5^3 = 500/3 pi
(W)
When the radius = 10mm, volume = 4/3 * pi * 10^3 = 4000/3 pi
(8W)
QN: What's the relation between mass and volume though? Is mass
= volume?
EDIT: Assume that both steel ball bearings have the same
density, D
Density = Mass / Volume
5mm Ball: D = Mass / (500/3 pi)
10mm Ball: D = Mass / (4000/3 pi)
5mm Mass = D * (500/3 pi) = 500D/3 pi
10mm Mass = D * (4000/3 pi) =4000D/3 pi
Since Weight = Mass * Gravitational Field Strength
5mm Ball Weight = 500D/3 pi * 9.81
10mm Ball Weight = 4000D/3 pi * 9.81
Therefore, the weight of the 10mm ball is 8 times that of the
5mm ball.