Notes, summaries, assignments, exams, and problems for Physics

Thermal Energy

Thermal energy is the average kinetic energy of the atoms or molecules in a substance.

Thermal Energy and Changes of State

When a change of state occurs, the energy transferred in heating up the substance is used to break the bonds between the molecules. The energy transferred does not increase the thermal energy but rather increases the internal energy of the substance.

Key Concepts

• The particles of a substance are in constant motion, and this increases as the substance heats up.
• Thermal energy is the average kinetic energy of the particles of a substance.
• During a change of state, the energy transferred in the heating process is used to break the bonds between molecules without increasing its thermal energy.

Temperature: Measurement

Angular Kinetics

Center of Mass

Point around which mass or weight is considered to be concentrated.

Determining COG

• Balance method
• Suspension method
• MRI reconstruction
• Segmental

Segmental Limitation

• Based on Caucasian male cadavers
• Completed in 1930s
• Based on segments being truncated cones

Mechanical Stability

Ability to maintain vertical projection of CG within base of support.

Ways to Increase MS

• Increase mass
• Increase friction between body and surface
• Increased size of base support

Angular Inertia

Property of an object to resist changes in its angular motion.

Factors Influence

Radius has larger influence than mass.

Center of Mass

Point where gravitational force is applied balance

Radius of Gyration

Point where mass can conceptually be concentrated such that it does... Continue reading "Angular Kinetics and Biomechanics" »

It is the view that our mind and our brain are different things. One way to understand this concept is to consider our self as a container including our physical body and physical brain along with a separate non-physical mind, spirit, or soul. The mind, spirit, or soul is considered the conscious part that manifests itself through the brain in a similar way that picture waves and sound waves manifest themselves through a television set. The picture and sound waves are also non-material just like the mind, spirit, or soul.

Elements of Design

1. Lines

• Vertical lines: Create height and grandeur.
• Horizontal lines: Establish relationships and calm the mood.
• Diagonal lines: Generate movement and direction.
• Curved lines: Convey familiarity, comfort, and relaxation.
• Thick lines: Direct the eye without distraction.

2. Shapes

3. Color

4. Value

5. Texture

6. Space and Perspective

Principles of Design

1. Space

2. Alignment

3. Repetition

4. Contrast

5. Pattern

6. Rhythm and Movement

7. Proportion

8. Balance

9. Unity

10. Emphasis

Principles of Design

1. Similarity

2. Continuation

3. Closure

4. Proximity

5. Figure

6. Symmetry

Anatomy of the Eye

The retina of the eye, lining the posterior two-thirds of the eyeball, is located within the inner tunic.

The jelly-like substance located between the lens and retina is the vitreous body.

True or false: Accommodation refers to the change in lens thickness in order to provide fine focus of an image. The answer is true.

Functions of the Vitreous Body:

• Maintains shape of eyeball
• Refracts rays of light
• Keeps retina smoothly pressed against inner surface of eye chamber

Hemidecussation occurs within the visual projection pathway at the optic chiasm.

Fundamental Forces in Physics

Weight (W)

• Weight is the gravitational force that exists between masses. Specifically, it is the force exerted on an object by a planet's gravity when the object is at the planet's surface.
• It can be calculated using the formula: W = mg
  • Where: m is the mass of the object under study, measured in kilograms (kg) in the SI unit system.
  • g is the acceleration due to gravity at the planet's surface. On Earth, g ≈ 9.81 m/s².
• Weight is directed along the line connecting the object under study with the planet's center, oriented towards the planet's center.

Normal Force (N)

• The Normal Force is a contact force that acts between two surfaces that are touching each other.
• It is often calculated indirectly, as it balances other forces

Simple Harmonic Motion and Waves

Vibrations and Frequency

At the equilibrium position of a mass attached to a spring, the velocity reaches a maximum.

Frequency is the number of cycles or vibrations per unit of time for a system in simple harmonic motion.

Sound and Pitch

The perceived highness or lowness of a sound is known as pitch.

The Doppler Effect

The Doppler Effect applies to all types of waves.

Electromagnetic Spectrum and Television

Radio waves are the portion of the electromagnetic spectrum utilized in television technology.

Electromagnetic Radiation in a Vacuum

In a vacuum, electromagnetic radiation of short wavelengths travels at the same speed as radiation of long wavelengths.

Mirrors and Refraction

Image Formation by a Flat Mirror

A flat mirror

Formulas to Calculate Pressure

P=pgh P=F/A Pabs=Pgauge+Patm P=Pa p=kg/m3 g=m/s2 h=m

Newtons and Pascal

P=Pa Pa=N/m2 Pa in 1 atm 101,325Pa

Archimedes Principle of Buoyancy

An object submerged in any fluid will experience a buoyant force equal to the weight of the fluid it has displaced.

Pressure

Air pressure in the wheels of the car, buoyancy: (the force that makes objects float) the boat floats because the fluid is denser than the object.

Buoyancy

Fw =m*g p=m/v Fb=Fa+Fw

Waves

Regards to medium mechanical waves (need a medium), electromagnetic (can propagate in a vacuum), regards to propagation longitudinal (parallel to the direction of the propagation), transverse (perpendicular), circular (waves on water, circular fashion).

Classify Sounds Waves

Lower... Continue reading "Physics Formulas and Concepts for Pressure, Waves, and Electricity" »