1 / 26

Learning Goals

Learning Goals. Explain the meaning of mass and describe the units for measuring mass. Distinguish between mass and weight. Define volume and explain how the volume of matter is measured. Key Question: How do you measure mass and volume?. Measuring Mass and Volume. Measuring mass.

kirk-mullins
Download Presentation

Learning Goals

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Learning Goals • Explain the meaning of mass and describe the units for measuring mass. • Distinguish between mass and weight. • Define volume and explain how the volume of matter is measured.

  2. Key Question: How do you measure mass and volume? Measuring Mass and Volume

  3. Measuring mass • Mass describes the amount of matterin an object. • The SI unit for mass is the kilogram (kg). • The kilogram is too large a unit to be convenient for small masses. One gram (g) is one-thousandth of a kilogram. What is the estimated mass of ONE zinc nut?

  4. Matter • Matter is anything that has mass and takes up space. • All matter has mass. • Steel, plastic, rubber, and glass are different kinds of matter. A car has a lot more of each kind of matter than a bike.

  5. Mass and weight are different • We tend to use the terms mass and weight interchangeably, but they are not the same thing. • Mass is the amount of matter in an object. • Weight is a measure of the pulling force of gravity on an object.

  6. Mass and weight are different • A 2.3 kg bag of flour has a mass of 2.3 kilograms no matter where it is in the universe. • The weight of the bag of flour is less on the moon. The 5 lb bag of flour on Earth weighs only .8 lbs on the moon!

  7. Volume • Volume is the amount of space an object takes up. • The fundamental unit of volume in SI is the cubic meter (m3). • More convenient smaller units are cubic centimeters (cc or cm3), liters (L) and milliliters (mL).

  8. Volume • Measuring the volume of liquids is easy. • Pour the liquid into a graduated cylinderand read the meniscus at eye level.

  9. Displacement • You can find the volume of an irregular shape using a technique called displacement. • Put the irregularly shaped object in water and measuring the amount of water displaced.

  10. Comparing mass and volume • Mass and volume are two different properties of matter. • Size does not always indicate an object’s mass! • How the matter is packed into space is more important.

  11. Learning Goals • Define density in terms of mass and volume. • Identify units used to express the density of materials. • Apply the density formula to solve problems.

  12. Key Question: How is an object’s density related to its volume, mass, and tendency to sink or float? Density

  13. Density • Density describes how much mass is in a given volume of a material.

  14. Density • Solids, liquids and gases are matter, so they all have density. • The density of water is about one gram per cubic centimeter.

  15. Density • The units used for density depend on whether the substance is solid or liquid. • For liquids use units of grams per milliliter (g/mL) • For solids use density in units of g/cm3 or kg/m3.

  16. Density of common materials • Density is a property of material independent of quantity or shape.

  17. Density of common materials • Liquids tend to be less dense than solids of the same material. • Ex. solder (“sodder)

  18. 2.2 Density of common materials • Water is an exception to this rule. • The density of solid water (ice) is less than the density of liquid water.

  19. Determining Density • To find the density of a material, you need to know the mass and volume of a solid sample of the material. • Mass is measured with a balance or scale. • Use the displacement method or calculate the volume.

  20. Density Density changes for different substances because: • Atoms have different masses. • Atoms may be “packed” tightly or loosely.

  21. Solving Problems Calculating Density • Looking for: • …the density of the candle • Given: • …mass = 1500 g; volume = 1700 mL • Relationship: • D = m/V • Solution: • 1,500 g ÷ 1,700 mL = 0.8823529 g/mL # Sig. fig = .88 g/mL

More Related