Notes

Work, Energy, and Power

Equations:

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Notes:

• Work is the net force applied to an object multiplied by the distance it moves.

• Work is a vector, considering force direction.

• Positive work when force aligns with displacement, negative when opposite.

• Zero work if no displacement or force is perpendicular.

• A watt is the unit of power.

Heat

Notes:

• Heat is a measure of total energy.

• Temperature measures kinetic energy only.

• Kelvin is an absolute scale, with 0 K around -273.15 ⁰C.

• Difference between heat and temperature: heat measures internal energy in joules.

Density

Equations:

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Notes:

• Density units: , .

• Hydrogen least dense at about 0.08 , Osmium most dense at 22,590 .

• Various units for density, SI unit is .

States of Matter

Notes:

• Solid: rigid, fixed shape.

• Liquid: not rigid, cannot be compressed, fixed volume.

• Gas: compressible, no fixed volume or shape.

• Kelvin is an absolute scale.

Buoyancy and Pressure

Notes:

• Pressure measures force per unit area.

• Units: Bar, Pascals, Atmospheres, Tor, psi.

• Buoyancy: tendency to float in a fluid, upward force exerted by fluid.

• Archimedes principle: buoyant force equals the weight of water displaced.

Latent Heat

Notes:

• Latent heat is the heat required to convert a solid into a gas or vapor without a change in temperature.

• It represents the energy needed for a phase transition.

• Latent heat is specific to each substance and depends on the substance’s characteristics.

• Common examples include latent heat of fusion (solid to liquid) and latent heat of vaporization (liquid to gas).

• Unit: Cals.

Understanding latent heat is crucial in various applications, such as climate science, cooking, and phase change materials in technology. It plays a significant role in determining the energy required for processes like melting, freezing, and boiling.

Electricity:

• Static electricity means it does not move

• Charge is the property of a particle that makes up everything else. two charged objects produce an electrical force that depends on the product of their charges.

• the electric force is stronger than gravity. it is 1036 times stronger than the gravitational force.

• A charge is a scalar property of matter that can cause it to experience a force in an electromagnetic field. Charge types may only be positive or negative.

• An uncharged object has a net zero and is neutral

• a charged object has a net amount of either positive or negative charge within it

• positive charges attract negative and repel positive

• negative charge attract positive and repel negative