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?
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.
Please explain both questions cuz i'm not really sure about it. thanks!
the liquid has the same mass as the vapour.. let liquid vol=v1, gas vol = v2, so density of liquid = m/v1, density of gas = m/v2, u take density of liquid divide by density of gas u get 1200.. ( not very certain)
volume of a sphere = 4/3*pi*r*r*r rite..? so u sub in 5mm, u get volume of ball1 = 125*4/3*pi.. and density = 125*4/3*pi*density of steel = W/gravity..
den for ball2 the larger ball, do the same thing.. u get 1000*4/3*pi*density of steel, which is equal to 8W/gravity lo..(damn certain)
Edited: thot W was mass.. haha.. but its the same anyway.. just remember density*vol = mass can liao..
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.