Page 500 - Canadian BC Science 9

Instant Practice— Measuring Volume
Determine the volume of liquids present in the following graduated cylinders.
900
C
A
100
90
80
70
60
50
40
30
20
10
B
25
20
15
10
800
700
600
500
482
MHR • Science Skill 7
Measuring Mass
Is your backpack heavier than your friend’s backpack? You can check by holding a backpack in each hand. The mass of an object is the amount of matter in a substance or object. Mass is measured in milligrams, grams, kilograms, and tonnes. You need a balance, such as a triple beam balance, for measuring mass.
Use the following steps to measure the mass of a solid object.
1. Set the balance to zero. Do this by sliding all
three riders back to their zero points. Using the adjusting screw, make sure the pointer swings an equal amount above and below the zero point at the far end of the balance.
2. Place the object on the pan. Observe what happens to the pointer.
3. Slide the largest rider along until the pointer is just below zero. Then move it back one notch.
4. Repeat with the middle rider and then with the smallest rider. Adjust the last rider until the pointer swings equally above and below zero again.
5. Add the readings on the three scales to find the mass.
How can you find the mass of a certain
quantity of a substance, such as table salt, that you have added to a beaker? First, find the mass of the beaker. Next, pour the salt into the beaker and find the mass of the beaker and salt together. To find the mass of the salt, simply subtract the beaker’s mass from the combined mass of the beaker and salt.
The mass of the beaker is 160 g.