2nd Q Review

13a - explain that energy is conserved according to the law of conservation of energy as energy is transformed from one form to another 13b - explain the relationship between potential and kinetic energy 13c - compare and contrast the different forms of energy Energy is the ability to do work or cause a change. Mechanical Mechanical Energy is the energy associated with the motion of an object You have mechanical energy when you run or walk – combo of kinetic and potential Thermal Thermal Energy is the total amount of energy in all of the particles Movement of particles contained in a sample of matter. Heat, itself is not a form of energy but it IS thermal energy that is transferred between two objects of different temperatures. Chemical Chemical Energy is the energy stored in chemical bonds (the atoms of Energy from a battery, the food you eat, elements that make up a compound are held together by chemical bonds) given off in a chemical reaction Electrical Electrical Energy is the energy that results from moving charges computers and televisions are examples of electrical devices that operate using electrical energy Light/Electromagnetic Electromagnetic Energy is the energy resulting from the motion of the examples include light, microwaves, and X- particles within atoms rays Sound Sound Energy is the energy given off by a vibrating (rapid, back-and-forth motion) object. The energy travels through matter in the form of waves. Nuclear Nuclear Energy is the energy stored in the nucleus of an atom as a result of the nuclear forces. This form of energy can be released from the atom through nuclear fission (splitting of atoms) or nuclear fusion (joining of atoms).

13d - explain how heat is transferred through matter by conduction, convection and radiation Heat – transfer of thermal energy between objects with different temperatures. Conduction – heat transferred via direct contact between objects – metal spoon getting hot in soup, feet touching hot sand, burning hand on iron Convection – heat circulating through a fluid (gas or liquid) – heating/air conditioning systems, boiling water, land/sea breezes Radiation – heat transferred through air or vacuum – warming hands by a fire, sun warming the earth 13e - explain how heat causes matter to expand and contract Thermal Expansion – increases in temperature = increases in particle movement/energy. More movement = more distance between particles. 13f - explain the difference between heat and temperature Heat – transfer of thermal energy between objects with different temperatures. Temperature – average kinetic energy of the particles in an object. 17a - explain how waves transfer energy Waves transfer energy through the vibration of particles in a medium Medium – the stuff through which a wave travels 17b - identify the structure, movement, and properties of electromagnetic and mechanical waves Transverse Waves – all EM waves are Transverse, do not need a medium to travel, particles move perpendicularly to the energy. Crest – top of wave, Trough - bottom of wave, Mechanical waves – need a medium to continue, particles move in the same direction as the energy, eg. Sound waves Rarefaction – spread out portion of wave, Compressions – close together portion of waves 17c - describe how the behavior of light and sound waves is affected by mediums such as air, water and/or solids Sound travels fastest through solids because the particles are closer together than in a gas Reflection – wave bounces off of a barrier – sound waves bouncing are Echoes, Law of Reflection – angle in = angle out Refraction – waves bends as it enters a different medium and changes speed – pencil in water Diffraction – waves bend around a barrier or bend through an opening – why we can hear around a corner or see light down a hall Interference – when waves overlap Constructive- 2 crests or 2 troughs overlap and increase wave amplitude. Destructive – a crest and trough overlap and decrease or cancel out the wave’s amplitude. 18a - explain how refraction is used to separate light into the colors of the spectrum White light has all the colors in it – each with its own wavelength – as the white light changes medium and speed each wavelength refracts at its own angle separating the white light into its components. Think Pink Floyd prism album cover. 18b - investigate and discuss how light interacts with mirrors (reflection) and lenses (refraction) to produce images Reflection top- convex lens bottom-concave lens Doppler Wave structure – Transverse 18c - explain how the human eye sees objects and colors in terms of wavelengths 18c1 - explain how light responds to reflection, refraction, diffraction, and absorption Reflection – wave bounces off of a barrier – sound waves bouncing are Echoes, Law of Reflection – angle in = angle out Refraction – waves bends as it enters a different medium and changes speed – pencil in water Diffraction – waves bend around a barrier or bend through an opening – why we can hear around a corner or see light down a hall Absorption – waves transfer energy from light to particles of matter – not reflected. Can cause objects to warm up. Black shirt in summer. 18c2 - explain how wavelengths of light are absorbed and/or reflected in order for the human eye to see color We see because light bounces (reflects) off of objects. We see only the colors that have reflected. The rest are absorbed. Red apple means red wavelength has reflected to our eyes. 19a - describe sound as a form of energy produced by vibrations Sound waves are impulses of energy bouncing into particles in front of the them like passing a message down a row of people. Longitudinal waves 19b - diagram the parts of the wave and explain how the parts are affected by changes in amplitude and frequency Increased frequency means either increased wave speed or shorter wavelength Increased amplitude means increased energy, no change in frequency, Rest positionIncreased wavelength means lower frequency 19c - relate the properties of sound to everyday experiences (i.e., Doppler effect, pitch, volume) Pitch – related to changes in frequency. Higher frequency = higher pitch Volume – related to changes in amplitude. Higher amplitude = louder volume = more energy see picture above Doppler Effect – the “smooshing” of waves as a sound comes toward you, causing a higher pitched sound, lower once it passes you. Sirens.