Name ____________________________________ Date _______________________ Period ________________
Homework – Due Friday, September 19, 2014
Mass – Refers to a measure of the amount of matter in an object. To calculate mass simply place the object on a TripleBeam-Balance
Volume - Refers to the amount of space an object occupies.
To find the volume of a rectangular solid, use the formula v = l x w x h.
Example: What is the volume of a rectangular box with a length of 6cm, a width of 5 cm, and a height of 2 cm?
v=l x w x h
v = 6cm x 5cm x 2cm
v = 60cm 3
To find the volume of a cube, use the formula v = s3.
Example: What is the volume of a cube with sides equal to 4cm?
v = s3
v =(4cm)3
v = 48cm3
To find the volume of an irregularly shaped object –use a method called water displacement
1.
Fill a graduated cylinder with enough water so that the object will be fully submerged when placed in the
graduated cylinder.
2. Read and record the volume of water.
3. Carefully slide the object into the water and then read and record the new volume.
4. Subtract the two volumes to see how much water was displaced – this is the volume of that object.
Example: What is the volume of an object that displaces 16 mL of water? 16cm3
Density – Density is the mass of a known object. Density is calculated using the formula
density = mass  volume
Example: What is the density of an object with a mass of 25g and a volume of 5 cm3?
(1) Write the formula
d=mv
(2) Put the given measurements into the formula
(3) Solve d = 5g/cm3
d= 25g  5cm3
Density Triangle
M
D
V
The density triangle can help you to remember the formula for finding density, mass, and volume when given the other
measurements.
Complete the following problems. Round your answers to the nearest hundredths place. Show all of your work and
don’t forget to include the units!
1.
What is the density of a box that has a volume of 412cm3 and a mass of 42g?
2.
Calculate the density of a 500g rectangular block with the following dimensions: length = 10cm, width = 5cm,
height = 8cm
3.
One side of a cube is 6cm in length. Its mass is 220g. What is the density of the cube?
4. You are given a cube with a volume of 8cm3. The density of the cube is 18g/cm3. What is the mass of the cube?
5. A piece of balsa wood has a density of .4g/cm3. Its mass is 500g. What is the volume of the piece of wood?
6. An irregular object with a mass of 118g displaces 25 mL of water when placed in a graduated cylinder. Calculate
the density of the object.
7. A screw has a mass of 10 grams. After dropping it in a graduated cylinder, you find its volume is 7mL. What is its
density?
8. A graduated cylinder is filled with 20mL of water. You then place a toy car very carefully into the graduated
cylinder and observe that the water level is now at 32mL. The car has a mass of 144g. What is the density of the
toy car?
9 – 15. Complete the table below in regards to whether you think the object will float, neither float nor sink, or sink
when placed in the given fluid.
9.
10.
11.
12.
13.
14.
15.
Density of Object
17 g/cm3
1 g/cm3
4.17 g/cm3
4 g/cm3
1.02 g/cm3
2.37 g/cm3
8.98 g/cm3
Density of Fluid
17.4 g/cm3
3 g/cm3
4.17 g/cm3
4 g/cm3
1.01 g/cm3
6.07 g/cm3
8.95 g/cm3
Float, Neither float nor sink, or sink?