level: Level 1 of Chapter 7 : Matter and materials
Questions and Answers List
level questions: Level 1 of Chapter 7 : Matter and materials
| Question | Answer |
|---|---|
| Define density | Mass per unit volume of a substance |
| What is the formula for density | Mass / volume |
| What is the formula for pressure | Normal force ÷ cross-sectional area |
| What are the units of pressure, what is the special name given? | Newtons per square meter (N m^-2) Pascals (Pa) |
| Pressure of a fluid depends on 3 factors | 1. Depth h below the surface 2. Density p of the fluid 3. Acceleration due to gravity g |
| What is the formula for change in pressur | Density × acceleration due to gravity × depth |
| What does Archimedes' principle state | States that the upthrust on a body is equal to the weight of the liquid or gas thqt it displaces |
| What is the volume of the liquid displaced equal to? | Is equal to the volume of the liquid taken up by the object |
| Spring is being squashed and shortened we say that the forces are ... | Compressive |
| What is the formula for spring constant? | Force ➗ extension |
| What is the Si unit for the force constant | Newtons per meter or N m^-1 |
| ()When does a material obey Hooke's law | A material obeys Hooke's law if the extension produced in it is proportional to the applied force (load) |
| Define strain | Strain is defined as the increase in length of a wire (its extension) divided by its original length |
| What is the formula used to calculate strain? | Extension ➗ original length |
| What is the formula used to calculate stress | Normal force ➗ cross-sectional area |
| What is Young Modulus? | Ratio of stress to strain |
| What is the formula used to calculate Young modulus? | stress ➗ strain |
| What do we call the energy in a deformed solid? | Elastic potential energy or strain energy |
| What is the formula used to calculate elastic potential energy? | ½ Fx |
| What is the unit of pressure | Pascals Pa |