RP5 Density

Question 1

(regularly shaped objects) outline the basic steps of the practical.

Answer 1

1. measure the dimensions of the regular shape and calculare the volume
2. measure the mass of the shape using a calibrated balance
3. calculate density from the mass and volume

Question 2

(regularly shaped objects) give the formula for the volume of a prism

Answer 2

volume = area of face x height

Question 3

(regularly shaped objects) what equation is used to calculate volume of a rectangular prism?

Answer 3

volume = length x width x height
(this also applies to cubes)

Question 3

(regularly shaped objects) give the formula for the volume of a sphere

Answer 3

volume = 4/3 x π x radius^3
v = 4/3πr^3

Question 3

(regularly shaped objects) what equation is used to calculate density?

Answer 3

density = mass / volume

Question 3

(regularly shaped objects) whjat piece of equipment is used to measure the object’s mass? what must you do before using it?

Answer 3

a digital balance, which should be seroed before placing the object on it to avoid a zero error.

Question 4

(regularly shaped objects) what unit is used for density?

Answer 4

kg/m^3

Question 5

(regularly shaped objects) how do you convert from g/cm^3 to kg/m^3?

Answer 5

multiply the value by 1000

Question 6

(irregularly shaped objects) outline the basic steps of the practical.

Answer 6

1. measure the mass of the irregular shape
2. fill a displacement can with water and submerge the object
3. record the volume of water that has been displaced
4. calculate the density from the mass and volume

Question 7

(irregularly shaped objects) what should you place under the can spount to collect the water?

Answer 7

a measuring beaker.

Question 8

(irregularly shaped objects) explain how you should fill the displacement can to get the most accurate results.

Answer 8

fill the can until water starts to drip out of the spout and into the beaker. wait until the dripping just stops before submerging the object.

Question 9

(liquid) outline the basic steps of the practical.

Answer 9

1. meaure the mass of the empty measuring cylinder
2. pour around 100cm^3 of liquid into the cylinder and record the volume
3. measure the mass of the cylinder with liquid in, and subtract the cylinder’s mass to calculate the mass of liquid
4. calculate density from mass and volume

Question 10

(liquid) how does the density of solids and liquids compare?

Answer 10

in general, solids are more dense than liquids since their particles are more tightly packed together meaning there is more mass per unit volume.