Problem Description:
We are tasked with calculating the volume of three objects (a glue stick, a pencil, and a toy block) using the water displacement method. The initial volume of water in each graduated cylinder is given as 15 mL. The final volumes after placing each object into the water are shown in the images. We need to determine the volume of each object by finding the difference between the final volume and the initial volume.
Given Information:
- Initial volume of water in each cylinder:
15 mL
- Final volumes for each cylinder are shown in the images:
-
Glue Stick (B): Final volume = 20 mL
-
Pencil (C): Final volume = 20 mL
-
Toy Block (D): Final volume = 18 mL
Solution Approach:
The volume of an object can be calculated using the water displacement method as follows:
\[
\text{Volume of Object} = \text{Final Volume} - \text{Initial Volume}
\]
#### Step 1: Calculate the volume of the glue stick.
- Initial volume = 15 mL
- Final volume = 20 mL
\[
\text{Volume of Glue Stick} = 20 \, \text{mL} - 15 \, \text{mL} = 5 \, \text{mL}
\]
#### Step 2: Calculate the volume of the pencil.
- Initial volume = 15 mL
- Final volume = 20 mL
\[
\text{Volume of Pencil} = 20 \, \text{mL} - 15 \, \text{mL} = 5 \, \text{mL}
\]
#### Step 3: Calculate the volume of the toy block.
- Initial volume = 15 mL
- Final volume = 18 mL
\[
\text{Volume of Toy Block} = 18 \, \text{mL} - 15 \, \text{mL} = 3 \, \text{mL}
\]
Final Answers:
\[
\boxed{5 \, \text{mL}, 5 \, \text{mL}, 3 \, \text{mL}}
\]
-
Glue Stick: 5 mL
-
Pencil: 5 mL
-
Toy Block: 3 mL
Explanation:
The water displacement method works because when an object is submerged in water, it displaces an amount of water equal to its own volume. By measuring the increase in the water level (final volume minus initial volume), we can determine the volume of the object. This method is particularly useful for irregularly shaped objects where direct measurement might be difficult.
Parent Tip: Review the logic above to help your child master the concept of water displacement method worksheet.
