particles - density Flashcards
calculation, practical 5
1
Q
what is the equation for density
A
density = mass/volume
p = m ÷ v
mass - kg
volume - cubic metres
density - kg/m^3
(can also be g/cm^3)
2
Q
what is density
A
the mass of a material per unit of its volume
3
Q
what to do for regular solids in practical 5: measuring density
A
- use a RULER to measure the length, width, and height of the block (mm precision)
- multiply these to find the volume of the regular shape
- use an electronic balance to determine mass of the block
- calculate density of the regular shape using p = m ÷ v
4
Q
what to do for irregular solids in practical 5: measuring density
A
- fill a eureka can with water until it is flowing out of the spout
- wait until the spout stops dripping water and then place a measuring cylinder under the spout
- attach a string to the irregular object so you can carefully lower it into the can
- the water flowing out of the spout will collect in the measuring cylinder which is the volume of the object
- use an electronic balance to determine the mass of the irregular object
- calculate density of the irregular shape using p = m ÷ v
5
Q
what to do for liquids in practical 5: measuring density
A
- find the mass of an empty measuring cylinder
- add 20cm^3 of the salt solution into the cylinder (measure with care)
- place the filled cylinder on electronic balance - record the mass - subtract the mass of the empty cylinder
- once you have the mass of the solution, repeat the steps for 5 other volumes of the solution and record results in a table
- plot a graph of mass (y) against volume (x) and calculate the gradient of the line of best fit to get the density