Waves, Sound, Modern Physics and Electromagnetic Spectrum

Vibrations can give rise to waves – which travel outward from the source – such as waves in a cord, earthquake waves, and water waves. How do the Spiders detect their pray? How does a T.V. or Radio set work? Can you hear me??? So it is due to at least 4 vibrating things………….make a guess !!!! What is equilibrium position? What is restoring force? S.H.M. Hook’s Law : F = - k x What does the minus indicate? What is k? During oscillation of such a mass which of the following remains constant? a) Force b)mass c)acceleration of mass d) All the given Multi optional Qn: Which of the following represents a S.H.M.? p: F = -3 Ө q: F = -k y r: F = 6 x s: F = - 0.4 x2 p, q b) q, r c) r, s d) p, q, r, and s Natural frequency Forced Vibration Resonance Can you list some uses of Resonance? What is sound and how does it travel? What do waves consist of? Can we see the energy in sound waves? What is this? Which travels faster? a)Jet Airoplane b)Sport Car c)Sound d)Cheeta What happens when there is a change in the material through which the sound travels? Why it is harder for sound to pass through gases than through liquids? Which is more elastic rubber or steel? Sound travels faster through denser air, as more molecules are squeezed and hence their bonds are stronger. Note the following different conditions: A: Cooler air at 20˚C. B: Warmer air at 40˚C. Which air is dense? [Answer A or B] Sound travel faster in A, or B? [read conditions above and Answer A or B] The formula to find the speed of sound in air is as follows: v = 331m/s + 0.6m/s * T in ˚C In fluorescent minerals, phosphorescence is an afterglow seen after the ultraviolet light source is turned off. One of the more famous minerals with long duration phosphorescence is calcite from the mercury mines So what makes the protons stay together in an atom? Does the nucleus of an atom ever lose particles? What is radioactivity? What is radioactivity? Review: Radioactivity is the release of energy and matter due to a change in the nucleus of an atom. Radioisotopes are isotopes that are unstable and release radiation. All isotopes are not radioisotopes. Transmutation occurs when a radioactive element attempts to become stabilized and transforms into a new element. Explain what the electromagnetic spectrum is and how scientists use it. What are Electromagnetic waves?