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:
Yes
Explanation:
There are two types of interference possible when two waves meet at the same point:
- Constructive interference: this occurs when the two waves meet in phase, i.e. the crest (or the compression, in case of a longitudinale wave) meets with the crest (compression) of the other wave. In such a case, the amplitude of the resultant wave is twice that of the original wave.
- Destructive interferece: this occurs when the two waves meet in anti-phase, i.e. the crest (or the compression, in case of a longitudinal wave) meets with the trough (rarefaction) of the other wave. In this case, the amplitude of the resultant wave is zero, since the amplitudes of the two waves cancel out.
In this problem, we have a situation where the compression of one wave meets with the compression of the second wave, so we have constructive interference.
Answer:
a) 1.20227 seconds
b) 0.98674 m
c) 7.3942875 m/s
Explanation:
t = Time taken
u = Initial velocity = 4.4 m/s
v = Final velocity
s = Displacement
a = Acceleration due to gravity = 9.81 m/s²


b) Her highest height above the board is 0.98674 m
Total height she would fall is 0.98674+1.8 = 2.78674 m

a) Her feet are in the air for 0.75375+0.44852 = 1.20227 seconds

c) Her velocity when her feet hit the water is 7.3942875 m/s
Answer:
Mass is constant everywhere,
But weight is different,
If earth g = 10 then moon's is 1.6666667
Now billie's weight in moon is 41.6667
There's no such thing as a wave of white light. Every light wave with
a certain wavelength has some color. White light is a mixture of all
the different wavelengths with all of the different visible colors.
They're ALL there in white light. When they all enter your eye at
the same time, your brain gets the message of brightness with
no particular color, which we call "white light".