Density
Density. Drill. Which type of emergency drill would Ms. Massella announce over the PA system if we had an earthquake? Where is our secondary evacuation location if we have a serious fire, or emergency drill, in the building?. Objectives. iWBAT Show mastery of safety rules on a safety quiz.
Density
E N D
Presentation Transcript
Drill • Which type of emergency drill would Ms. Massella announce over the PA system if we had an earthquake? • Where is our secondary evacuation location if we have a serious fire, or emergency drill, in the building?
Objectives • iWBAT • Show mastery of safety rules on a safety quiz. • predict whether an object has a higher or lower density than water. • solve density problems. • Perform a density lab to determine the density of an object.
Do you know the density of water? • What is the density of “pure” water? • The density of water is 1 g/ml
Sink or Float • Does a cork sink or float in water ? • Is the density of a cork more or less than 1 g/ml ?
Density Equation • Do you remember what the Density equation is from the Accuracy/Precision lab? • Density = _mass____ volume What are the units used for mass? What are the units used for volume? What would be the units for density?
Let’s try some problems. • Set up the equation and solve for density. • The mass of an object is 6.5g and the volume is 4.8 ml, what is the density of the object? • Ans: 1.35 g/ml
Let’s try some problems. • Solve for density. • The mass of an object is 1.09 g and the volume is 3.72 ml, what is the density of the object? • Ans: 0.29 g/ml
Let’s try some problems. • Set up the equation and solve for mass. • The density of an object is 5.12 g/ml and the volume is 7.07 ml, what is the mass of the object? • Ans: 36.2 g
Let’s try some problems. • Solve for mass. • The density of an object is 1.11 g/ml and the volume is 2.55 ml, what is the mass of the object? • Ans: 2.83 g
Let’s try some problems. • Set up the equation and solve for volume. • The density of an object is 10.2 g/ml and the mass is 4.99g, what is the volume of the object? • Ans: 0.49 ml
What happens if the object is a cube or rectangle? • Instead of using ml that you read off of a graduated cylinder, you can find the volume of the object by measuring with a meter stick. • Do you remember how to determine the volume of a cube? • Length x width x height
Cube volume units • If you use length x width x height to determine the volume, what will the units be? • The units will be cm3 • Note: If you multiply the numbers, you also need to multiply the units. • Ex: 3 cm x 2 cm x 1 cm = 6 cm3
Practice Problem • Set up the equation and solve for volume. • The density of block of metal is 0.65 g/cm3 and the mass is 2.47g, what is the volume of the object? • Ans: 3.8 cm3
Density Practice Problems • Pick up a copy of the Density worksheet. • Try working out the problems. • Remember to show all of your work.
Wrap Up • I will switch to the Sink or Float ppt.