Answer:
77.96dB
Explanation:
Recall that decibels are a unit of measuring intensity of sound, and depend on the logarithm of the intensity
the intensity, measured in decibels is given by:
I(db)=10log(I/I0)
I is the intensity in MKS units; I0 is the threshold intensity for human hearing (10^-12 W/m^2)
Thus, if the two sounds together have a dB of 81, we know:
81=10log(I/I0)
using the data above, we can find the intensity of the two sounds to be
0.000125 W/m^2
therefore, one firecracker has an intensity half of that, or 0.0000625W/m^2
now use this value to find the dB of one firecracker:
I(dB0=10log(0.0000625/10^-12)=77.96dB
I think the second choose, energy to be stored.
Answer:
What interference occurs when two waves are out of phase?
Image result for ______ interference occurs when two waves are out of phase.
Destructive interference
Destructive interference occurs when the maxima of two waves are 180 degrees out of phase: a positive displacement of one wave is canceled exactly by a negative displacement of the other wave. The amplitude of the resulting wave is zero.
Answer:
Explanation:
This does not violate Newton's 1st law because the net force would still be 0 in order to produce uniform motion (aka constant velocity). The other forces acting on the vehicles is air resistance which is non-zero. So we need car internal force to counter balance this force, which require extra gas for the car.
Answer:
Explanation:
Mechanical waves and electromagnetic waves are the types of waves we have. The major difference between this type of waves is that, while mechanical waves requires material medium for its propagation, electromagnetic waves does not require material medium for its propagation.
Example of mechanical waves are waves produced by a ripple tank.
Example of an electromagnetic waves are the electromagnetic spectrum which includes radio waves, infrared waves, visible light, ultraviolet rays etc... This waves are produced naturally without any medium compare to mechanical wave.
