Heat to heat transfer 

• Kinetic energy: energy of motion

• Heat: thermal energy or total of all energy within a substance

• Motion of molecules

  • Vibrates and moves in each state of matter

    • Solid: slowest

    • Liquid: faster than solid, slower than gas

    • Gas: fastest

• Law of Conservation of Energy: states that energy can neither created nor destroyed, it simply changes form

• Thermal energy in freezing and boiling materials

  • Freezing: decreases kinetic energy; molecules move slowly and closer together.

  • Boiling: increases kinetic energy; molecules move faster and farther apart.

• Solutes: salt (how it affects boiling and freezing)

  • Boiling: increases boiling point

    • Boiling point: the temperature at which a liquid becomes a gas

  • Freezing: decreases freezing point

    • Freezing point: the temperature at which a liquid becomes a solid

• Specific heat capacity: the amount of heat (joules) that is required to raise the temperature of 1 gram of a substance by 1 degree centigrade

• Joules: unit of energy

• Heat transfer: transfer of thermal energy from areas of high temperature to low temperature

Friction

• Frictional force: The force that prevents two objects from easily moving against one another

• Acceleration: the rate an object changes velocity

  • Positive acceleration: speed increases as it moves away from its starting position

  • Negative acceleration: speed decreases as it moves away from its starting position

• Relationship between weight and friction

  • The more weight, the more frictional force.

• Surface area in friction

  • Friction stays the same on an object, no matter the surface area

• What affects friction

  • The smoothness/roughness of the surface.

    • Smoother the surface, less friction

    • Rougher the surface, more friction

• Coefficient of friction: a number that describes the degree of mechanical and molecular interaction between forces

  • As friction increases, coefficient of friction increases

• Applied force: force that is applied to an object from an outside force

• FE = ma : the sum of all forces equal to mass x acceleration

Soundwaves

• Pressure waves: the moving wave that is produced by a standing wave moves back and forth

• Standing waves: a wave that forms in a vibrating object. This wave does NOT move through space, it forms due to the repeated vibrations of the object

• Frequency vs pitch

  • Frequency: the back and forth vibrations which causes sound to occur rapidly or slowly

  • Pitch: how high or low the sound is

  • Low frequency= HIGH PITCH

  • High frequency= LOW PITCH

• Speed of sound (in air and water)

  • Air: 346 m/s

  • Water: 1500 m/s

  • Greater attraction between particles = greater speed of sound

• Formula of speed (s=wavelength x frequency)

• Standing wave

  • 2 nodes: beginning + end

  • 2 antinodes: one up, one down