Answer:
r₂ = 0.2 m
Explanation:
given,
distance = 20 m
sound of average whisper = 30 dB
distance moved closer = ?
new frequency = 80 dB
using formula
I₀ = 10⁻¹² W/m²
now,
to hear the whisper sound = 80 dB
we know intensity of sound is inversely proportional to square of distances
r₂ = 0.2 m
The correct answer is<span> B.The speed of sound in air is directly proportional to the temperature of the air.
When the temperature increases so does the speed of sound. Sound is faster by </span>0.60 m/s for every higher degree in air temperature because the air density is reduced and the sound can travel faster.
Answer:
option C
Explanation:
given,
Force by the engine on plane in West direction = 350 N
Frictional force on the runway = 100 N in east
force exerted by the wind = 100 N in east
net force and direction = ?
consider west to be positive and east be negative.
when airplane will be moving there will be frictional as well as wind resistance will be acting in opposite direction of airplane
Net force = 350 N - 100 N - 100 N
= 150 N
as our answer comes out to be positive so the airplane will be moving in West
hence, the correct answer is option C
Answer:
An apple, potato, and onion all taste the same if you eat them with your nose plugged
Explanation:
<span>c. low frequency and low energy</span>
