Measurement and Density Review 1. What does a triple beam balance look like and what does it measures? Mass 2. What is a graduated cylinder and what does it measures? Volume 3. What is a meter stick or ruler and what does it measures? length 4. What is the basic unit of measurement for weight and mass in the metric system? gram 5. What are the units of measurement that we have been using for volume? Milliliter and cubic centimeters. (ml and cm3) 6. What are the units of measurement that we have been using for length?? Millimeter and centimeter (mm and cm) 7. Why do scientists use the metric system? 8. Define volume – the space an object takes up. 9. Define mass – the amount of particles an object contains. 10. Define weight – the force of gravity acting on an object. 11. Define length – distance from one point to another. 12. What are the similarities and differences between mass and weight? Be able to compare and contrast. 13. What is the formula for finding the volume of a regular solid? (length x width x height). 14. Be able to measure a line like the following in centimeters and convert to millimeters: _________________________________________ 15. Be able to read a triple beam balance like the following: 16. Know how to read a metric ruler and meter stick correctly. 17. Know how to convert between millimeters and centimeters. Know how to show your work! 18. Be able to calculate the density of different materials and compare (density = mass/volume). 19. Be able to analyze a problem and decide which material will float or sink based on density calculations (the higher density will always sink). 20. Be able to read a graduated cylinder. 21. Be able to calculate the interval spacing (directions below) on a variety of challenging graduated cylinders. 22. Be able to define a meniscus – the curvature of a liquid inside a graduated cylinder; always read from the bottom of the meniscus. 23. Know how to measure the volume of an irregular object such as a marble or a rock using either water displacement or an overflow canister. Calculating Intervals
Finding the interval of a graduated cylinder:
These are two identical graduated cylinders. 1
Start by picking any two numbers. 2
3
4
5
Let’s pick the numbers 10 and 15. Find the difference between these numbers: 15‐10 = 5 Now let’s put this together to find the interval.
•Find the difference between two numbers •Count the number of spaces between 10 and 15: •Divide the difference by the number of space:
15 ‐ 10 = 5 5 spaces 5 ÷ 5 spaces
So what does this mean? It means the each line of the graduated cylinder goes up by 1 ml.
So how do I find the volume of the egg in the graduated cylinder? This is simple. Remember to read from the bottom of the curve called the meniscus •First, find the volume of the water without the egg: •Next, find the volume of the water and egg together: •To get the volume of the egg, now just subtract the two numbers: •Now you have the volume of the egg: 4 ml 13 ml 13 ml – 4 ml 9 ml