Volume Miss Sauer’s 7 th Grade Science

Definition of Volume? Volume is the amount of space something occupies or the amount of space that something contains.

Different types of objects to measure: Solid-Regular Shaped Objects Liquid Solid-Irregular Shaped Objects An object is said to be REGULAR-Shaped if it has ALL RIGHT ANGLES. All the angles are 90 o in the corners, with three sets of parallel lines on every box. What is the difference between a regular-shaped object and an irregular-shaped object?

Solid-REGULAR Shaped Object Method: Measure each side & Multiply (length x width x height) Formula: V=l * w * h Units: cm 3 or m 3 (cubic units) Tools: Ruler

Volume = Length * Width * Height If we record length, width, & height: We record length in cm We record width in cm We record height in cm We get cm 3 when we multiply: cm * cm * cm = cm 3 If we record only length & height: We record length in cm We record height in cm We get cm 2 when we multiply: cm * cm = cm 2

Liquid Method: We take a direct measurement Formula: (none) Units: Liters (L) or milliliters (mL) Tools: Graduated Cyclinder

Solid-IRREGULAR Shaped Object Method: Record measurement of liquid before (this is your initial measurement) Add irregular-shaped object into the liquid (carefully!) Record liquid measurement after (this is your final measurement) Subtract initial measurement from final measurement Formula: V= V (final) – V (initial) Measure how much liquid that object displaces Units: Liters (L) or milliliters (mL) Tools: Graduated Cylinder

***REMEMBER*** 1 milliliter (mL) = 1 cubic centimeter (cc) = 1 centimeters cubed (cm 3 ) We need to remember this for when we compare volumes of different objects / liquids. 1m 3 = 1,000 L m 3   L (times by 1,000) But, when we compare cm 3 to mL: cm 3   mL (EQUAL)

Concepts for Reading a Graduated Cylinder Graduated Cylinder – “Graduated” means that the cylinder is marked with measured units. ****We must first determine the value of each mark when we are reading a measurement.**** Meniscus is the curve at a liquid’s surface by which you measure the volume of the liquid.

Proper Way To Read a Graduated Cylinder To measure volume correctly, read the scale at the lowest (the BOTTOM of the meniscus) part of the meniscus at eye level. Always check the unnumbered marks on a graduated cylinder to see how many sections there are and what they measure. Sometimes you have to estimate a measurement between two marks.

Closure Questions 1 cm 3 = _______ mL Can a regular shaped object’s volume be compared with an irregular shaped object’s volume? An object’s volume is 4.3 cm 3, another object’s volume is 5.2 mL. Which object has more volume? 4.3 cm mL 4.3 cm cm mL 5.2 mL