Answer:
ultrasound: high pitch, above the human range of hearing, reflects back
infrasound: longitudinal waves, in the human range, low pitch
Explanation:
Answer:
decibels (dB)
Explanation:
The sound intensity level is a quantity derived from the sound intensity.
The intensity of a wave is defined as the power of the source of the wave divided by the area through which the power of the wave is spread, mathematically:

where
P is the power of the source
is the surface area over which the wave spreads (assuming that the wave propagates in all directions, it corresponds to the surface area of a sphere of radius
, where r is the distance between the source of the wave and the observer)
For sound waves, the intensity is often expressed using another unit, called decibel (dB), defined as follows:

where
is the sound intensity level in decibels
I is the intensity of the sound wave
is the threshold intensity of a sound that a person can normally hear.
Answer:
The value is 
Explanation:
From the question we are told that
The distance of separation is 
The current on the one wire is 
The current on the second wire is 
Generally the magnitude of the field exerted between the current carrying wire is

Here
is the magnetic field due to the first wire which is mathematically represented as

Here
is the distance to the half way point of the separation and the value is

is the magnetic field due to the first wire which is mathematically represented as

Here
is the distance to the half way point of the separation and the value is
This means that 
So

=> 
=> 
=> 
Answer:
Magnitude of net force will be 432.758 N
Explanation:
We have given x component of acceleration 
And vertical component of acceleration 
Mass of the ball m = 0.40 kg
So net acceleration 
Now according to second law of motion
Force = mass × acceleration
So F = 0.40×1081.896 = 432.758 N
Answer:
remains the same, but the apparent brightness is decreased by a factor of four.
Explanation:
A star is a giant astronomical or celestial object that is comprised of a luminous sphere of plasma, binded together by its own gravitational force.
It is typically made up of two (2) main hot gas, Hydrogen (H) and Helium (He).
The luminosity of a star refers to the total amount of light radiated by the star per second and it is measured in watts (w).
The apparent brightness of a star is a measure of the rate at which radiated energy from a star reaches an observer on Earth per square meter per second.
The apparent brightness of a star is measured in watts per square meter.
If the distance between us (humans) and a star is doubled, with everything else remaining the same, the luminosity remains the same, but the apparent brightness is decreased by a factor of four (4).
Some of the examples of stars are;
- Canopus.
- Sun (closest to the Earth)
- Betelgeuse.
- Antares.
- Vega.