Answer:
Explanation:
Cosmologists refer to a "surface of last scattering" when the CMB photons last hit matter; after that, the universe was too big. So when we map the CMB, we are looking back in time to 380,000 years after the Big Bang, just after the universe was opaque to radiation. But the CMB was first found by accident.
plz mark as brainliest
False. p waves, than s waves
Answer:
1.4E-3J
Explanation:
Given that
Time = 8hrs = 28.8E3 seconds
Intensity= 90dB
D= 0.008m
Radius= 0.004m
So intensity is sound level Bis
10dBlog(I/Io)
I= 10 (B/10dB)Io
= 10( 90/10) x 10^-12
=0.001W/m²
But we know that
I = P/A
P= I πr²
= 5.02 x10^-8W
But energy is power x time
So E= 5.02E-8 x 28.8E3
= 1.4E-3J
Answer:
"where crests and troughs have their maxima at the same time"
Crests and troughs are 180 deg out of phase and when they have their maxima at the same time and place, their net contribution will be zero"