Answer:
. Doppler ultrasound is based on absorption of sound, and other
ultrasound technology is based on reflection.D.
Explanation:
Answer:
a. 2v₀/a b. 2v₀/a
Explanation:
a. Since you are moving with a constant velocity v₀, the distance, s you cover in time = t max is s = v₀t.
Since the dragster starts from rest with an acceleration, a, using
s' = ut + 1/2at² where u = 0 and s' = distance moved by dragster
s' = 0t + 1/2at²
s' = 1/2at²
Since the distance moved by me and the dragster must be the same,
s = s'
v₀t. = 1/2at²
v₀t. - 1/2at² = 0
t(v₀ - 1/2at) = 0
t= 0 or v₀ - 1/2at = 0
t= 0 or v₀ = 1/2at
t= 0 or t = 2v₀/a
So the maximum time tmax = 2v₀/a
b. Since the distance covered by me to meet the dragster is s = v₀t in time, t = tmax which is also my distance from the dragster when it started. So, my distance from the dragster when it started is s = v₀(2v₀/a)
= 2v₀/a
Answer:
A) 
B) 
C) 
D) mosquitoes speed in part B is very much larger than that of part C.
Explanation:
Given:
- Distance form the sound source,

- sound intensity level at the given location,

- diameter of the eardrum membrane in humans,

- We have the minimum detectable intensity to the human ears,

(A)
<u>Now the intensity of the sound at the given location is related mathematically as:</u>
..........................................(1)



<em>As we know :</em>


is the energy transferred to the eardrums per second.
(B)
mass of mosquito, 
<u>Now the velocity of mosquito for the same kinetic energy:</u>



(C)
Given:
- Sound intensity,

<u>Using eq. (1)</u>



Now, power:



Hence:




(D)
mosquitoes speed in part B is very much larger than that of part C.
The type of medium affects a sound wave as sound travels with the help of the vibration in particles. As different mediums have different amount and size of particles, for example, the speed of sound is faster through solid than liquid as solids have closely packed particles whereas liquids are loosely packed. Therefore the vibration is quicker in solids than liquids.
Hope it helps you! :)