SOUNDS.pptx ENERGY VIBRATION affected by medium and temperature

SOUND WAVES

1. LC 11: Investigates the effect of temperature to speed of sound through fair testing. (S8FE-Ie-25)

2. How Temperature Affects the Speed of Sound; Properties of Sound (reflection and refraction)

3. Objectives:   1. Determine how the temperature of the medium affect the speed of sound through video analysis 2. Explain the relationship between the temperature, kinetic energy and number of collision per unit time. 3. Solve for the speed of sound in air. 4. Cite real-life applications of how reflection and refraction are manifested in sound.

4. Rank the phases of matter (solids, liquids, and gases) in terms of its ability to transmit sound. *Why does sound travel fastest in solids and slowest in air?

5. EFFECT OF TEMPERATURE TO SPEED OF SOUND (Group 1) 1. SOUND is a vibration that is moving through a medium. These 2. VIBRATION will cause movement to the nearby air molecules. In this way, the vibration will spread out from the bell in the form 3. WAVES . Sound requires 4. MEDIUM to travel through! Molecules are particles are necessary to carry the sound wave. 5 . SOUND WAVES cannot travel in space or in a vacuum.

6. Sound Propagation (Group 2) In gases , such as the air around us, the molecules are 6. far apart /closer from each other. The molecules in liquid, such as water are a bit 7. Closely arranged / far apart since there are a lot of molecules to vibrate, sound waves require less time to move through the molecules of liquid. In solids, the molecules are 8. closely packed /far apart than they are in air and water. Based on the molecular arrangement of the different media, sound will travel more 9 . slowly /faster through the air and much more 10. quickly /slower through solids.

7. FACTORS THAT AFFECT SOUND (Group 3) 11. ELASTICITY is the ability of a material to return to its original form after an amount of force is applied. 12. Sound travels FASTER within a more elastic objects. 13. DENSITY is the amount of mass per area of space or volume of material. 14. Sound travels faster in LESS DENSE objects. 15. HIGH is the degree of hotness of coldness of a material. 16. Sound travels faster with HIGHER temperature.

8. SPEED OF SOUND IN AIR -331 m/s at 0 C (Group 4) v=331m/s + (0.6 m/s/ C) x T where : v= speed T= Temperature Example 1: The atmospheric temperature in Baguio City is 35 C. How fast does sound travel in the air? Given : 35 C (temperature) Unknown : Speed of Sound Formula : v = 331 m/s + (0.6 m/s/ C) T Solution : v= 331 m/s + (0.6 m/s/ C) 35 C v=331 m/s + 21 m/s Answer : v= 352 m/s

9. Example no. 2 What is the temperature of air if the speed of sound is 342 m/s. Given : 342 m/s (speed of sound) Unknown : Temperature Formula : v= 331 m/s + (0.6 m/s/ C) x T Solution : 342 m/s = 331 m/s + (0.6 m/s/ C) x T 342 m/s – 331m/s = 0.6 m/s/ C x T 11 m/s = (0.6 m/s/ C) x T Temperature : 11 m/s / 0.6 m/s/ C Temperature 18. 33 C

10. PROPERTIES OF SOUND ( Group 5) 21. Reflection is the turning back of wave as it hits a barrier Example : echo 22. Sound reflection occurs when soundwaves bounce back from the surface of a solid or liquid. 23. Refraction is the bending of sound waves as they pass from one medium to another. 24. Sound waves travel faster in warmer air than in 25. cooler air. 26. Refraction of sound at daytime 27. Refraction of sound at night time

11. Why does sound travel faster in summer (hot season) than in winter(cold season) ? Speed of sound depends on the 1. __________ of the medium. 2__________the temperature of the medium, more of the 3_______________and vice versa. Air is the medium. During summer season the temperature of air 4__________. At higher temperatures, the molecules of air has more 5. ________energy, hence, they vibrate 6. faster/slower . During winter season, the temperature of air 7. Increases/decreases. With the decrease in temperature, the kinetic energy of the molecules also 8. Decreases/increases. Molecules 9. do not / do vibrate much. As a result , the speed of sound 10. decreases / increases during winter season .

12. Application * Reflection of sound used to measure the speed and distance of underwater objects called SONAR. * Working of a STETHOSCOPE – the sound of patient’s heartbeat reaches the doctor’s ear through multiple reflection of sound. * Ultrasound images are created by reflected sound waves returning back to the tranducer . * A balloon, filled with a gas different from air, will refract sound waves. A gas denser air turns this balloon into a converging lens and a lighter gas makes it a diverging lens.