Sound waves in air are a series of <span>periodic disturbances, </span><span>periodic condensations and rarefactions,</span><span> and high- and low-pressure regions. It is all of the above. The answer is letter D.</span>
Answer:
б / 
Ф ( б / )
Explanation:
<u>Develop a suitable set of dimensionless parameters for this problem</u>
The set of dimensionless parameters for this problem is :
б /
Ф ( б / )
and they are using the pi theorem, MLT systems
attached below is a detailed solution
Total internal reflection causes light to be completely reflected across the boundary between the two media but not transmitted.
<h3>What is total internal reflection?</h3>
The term total internal reflection occurs when light is moving from a denser to a less dense medium such as from glass to air. This phenomenon occurs at the interface between the two media.
There are two conditions necessary for total internal reflection and they are;
1) Light must travel from a denser to a less dense medium
2) The angle of incidence in the denser medium must be greater than the critical angle.
Total internal reflection causes light to be completely reflected across the boundary between the two media but not transmitted.
Learn more about total internal reflection:brainly.com/question/13088998
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Answer:
59.4 meters
Explanation:
The correct question statement is :
A floor polisher has a rotating disk that has a 15-cm radius. The disk rotates at a constant angular velocity of 1.4 rev/s and is covered with a soft material that does the polishing. An operator holds the polisher in one place for 4.5 s, in order to buff an especially scuff ed area of the floor. How far (in meters) does a spot on the outer edge of the disk move during this time?
Solution:
We know for a circle of radius r and θ angle by an arc of length S at the center,
S=rθ
This gives
θ=S/r
also we know angular velocity
ω=θ/t where t is time
or
θ=ωt
and we know
1 revolution =2π radians
From this we have
angular velocity ω = 1.4 revolutions per sec = 1.4×2π radians /sec = 1.4×3.14×2×= 8.8 radians / sec
Putting values of ω and time t in
θ=ωt
we have
θ= 8.8 rad / sec × 4.5 sec
θ= 396 radians
We are given radius r = 15 cm = 15 ×0.01 m=0.15 m (because 1 m= 100 cm and hence, 1 cm = 0.01 m)
put this value of θ and r in
S=rθ
we have
S= 396 radians ×0.15 m=59.4 m
