VIBRATIONVIBRATIONVIBRATIONVIBRATION

WHAT IS VIBRATION• Shuffle motion periodically

(repeated) through balance point

Example in daily• Shivering • Guitar strings • Drum skin & other musical

instrumet• Heartbeat • Technology : USG (3&4 D)

Glossarium• Frekuensi : Number of events in one

time

f (Hertz) = Hz

Periode : Length of time required for a single event

T (Sekon) = s

CO-AL• Drum skin vibrate continuously as many

as 240 times a minute. What is the frequency of vibration of the drum skin

• Answer f = 240 / 60 = 4 Hertz

» T = 60/ 240 = 1 / 4 s

Test• At the sate Pak Mien restaurant an

employee using bamboo fan. If employees are fanning back and forth 150 times within 1 minute. What is the frequency and the period of the bamboo fan?

Rehat• Sebuah KRL berangkat dari Jakarta

menuju Bogor. Jika tidak ada angin alami yang bertiup. Ke arah manakah asap KRL tersebut?

U

S

TB

WAVE

WHAT IS WAVE

• A wave is a disturbance that propagates (travels) through space and time, usually by transference of energy

WAVE IN DAILY

• Mechanical Waves are waves which propagate through a material medium (solid, liquid, or gas) , usually by transference of energy, e.g Sound

• There are also waves capable of traveling through a vacuum, e.g. electromagnetic radiation (including light, ultraviolet radiation, infrared radiation, gamma rays, X-rays, and radio waves)

WAVE IN DAILY

• There are two basic types of wave motion : longitudinal waves and transverse waves

Longitudinal Waves

• In a longitudinal wave the particle displacement is parallel to the direction of wave propagation e.g Sound

Transverse Waves

• In a transverse wave the particle displacement is perpendicular to the direction of wave propagation e.g Light

So• The Sound is include in :

• The Ligth is include in :

GLOSSARIUM• T = periode (s)• f = frekuensi (Hz)• λ = wavelength (m)• v = wave velocity (m/s)

• v = λ / T or v = λ . f

Co- al• If a water wave need 2 sekon to

make a one full wave. Find frekuency and the velocity!

• In 2 seconds there is 10 waves in the medium of 50cm water surface. What is v, λ, f and T ?

PICTURE

Practice• Please open your orange-blue

book pg.154. Between number 1-30, what do you want to choose the odd or the even problems?