RP- Density Flashcards
What is density?
Density is a substance’s mass per unit of volume.
What is the equation for density?
Density (g/cm^3) = mass (g) / volume (cm^3)
How do you calculate the density of a regular shaped solid?
1) using a ruler, measure the length, width, and height of the cuboid, then calculate the volume of the cuboid by using l x w x h.
2) or… use vernier callipers to measure the diameter of the sphere, then calculate the volume of the sphere using 4/3pi(d/2)^3
3) place the shape on a top pan balance and measure it’s mass.
4) use the measurements and the density equation to calculate the density.
How do you calculate the density of an irregular shaped object?
1) place the object on the top pan balance and measure its mass.
2) fill this displacement can untill the water is level with the bottom of the pipe.
3) place a measuring cylinder under the pipe ready to collect the displaced water.
4) carefully drop the stone into the can and wait until no more water runs into the cylinder.
5) measure the volume of the displaced water.
6) use the measurements and the density equation to calculate the density.
How do you calculate the density of water?
1) place the measuring cylinder on the top pan balance and measure it’s mass.
2) pour the amount of water in the measuring cylinder and measure its new mass and the volume.
3) subtract the mass in step 1 from the mass in step 2. You now have the mass of the water.
4) use the measurements to calculate the density using the density equation.
What can you calculate the density for?
Regular solids, irregular solids, and liquids.
Densities calculated from measurements are subject to experimental error. What could have happened to the top pan balance to make this happen?
The top pan balance used by different people may not be identically calibrated.
Densities calculated from measurements are subject to experimental error. What could have happened to the measuring cylinder to make this happen?
The resolution of the cylinders may be different, causing different values for the volume recorded.
Densities calculated from measurements are subject to experimental error. What could have happened to the displacement can to make this happen?
The displacement can may not have been set up correctly each time and any additional drops of water would cause some to dribble out of the spout before use.
What is a hazard and control measure you would have to implement during this practical?
Hazard- water spilled from displacement can
Consequence- slip and fall
Control measure- use a measuring cylinder to collect displaced water and prevent spills
