Noise Pollution

Question 1

How has aircraft design made the quieter

Answer 1

Acoustic insulation
Chevron nozzles with serrated edges on outer cowlings reduce turbulence

Question 2

Why is decibel scale logarithmic

Answer 2

Human ear responds to wide range of sound power levels so an increase of 10db represents a 10x increase in volume

Question 3

Effects of noise pollution on living organisms

Answer 3

Disturb communication eg echolocation
Difficulties finding food
Migration changes
Disrupts mating
Hearing loss

Question 4

What are cowlings on aircraft

Answer 4

Engines on side wings of plane

Question 5

What are chevron nozzles

Answer 5

Serrated trailing edge on outer cowling

Question 6

What is a by pass ratio on aircraft

Answer 6

Ratio between mass flow rate of air drawn into engine and mass flow rate through engine core

Question 7

Effect of noise pollution on non living objects

Answer 7

Acoustic fatigue- structural failure due to vibrations
Shock impact- forces of impact after sudden loud noises damages buildings