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density
Question | Answer |
---|---|
what is density | Density is the mass of 1cm³ of a substance |
how do you find the density of an object | to find the density of an object you have to divide the mass by the volume |
what is the standard unit for density | the standard unit (SI) for density is kg/m cubed |
what unit is commonly used for density | g/cm cubed |
Can the density of an object change? | yes |
Changing the density of an object | The density of an object can change if either the mass or volume of the object is changed When liquids and gases are heated their volumes change and their densities change as a result |
How does density change when we heat/cool liquids or gases? | When volume increases, density decreases. When volume decreases, density increases. |
Why is density important? | Flotation, A knowledge of density can help us predict whether something sinks or floats This is useful for choosing materials for designing items that need to float e.g. life jackets |
Why is density important? substance | Substance identification A knowledge of density can help us predict what the substance is e.g. geologists use density to identify rock types |
why is density important? engineering | Engineering A knowledge of density can help us design different objects Some goods are designed to make them easier to carry e.g. MacBook Air and suitcases Energy efficient cars use low density materials to keep them light, saving fuel |
How does an iron ship float? | How does an iron ship float when iron(7.874 g/cm³) is denser than water (1g/cm³)? An iron ship floats because the average density of the ship is less than water Inside the iron sides of a ship is a large pocket of air pocket which helps flaot |
how does an iron ship float? | the iron is spread out so the average density of the iron is less than the density of water |