Answer:
it cannot be considered a physical change because it occur from the chemical reaction.
Explanation:
because physical change is the change of the size,volume, density,flexibility. in other words its a change in the outer appearance or change in which we can see or feel without using a tool or a machine
hope it help just my opinion
ANSWER
625 m/s
EXPLANATION
Given:
• The frequency of the sound wave, f = 250 Hz
,
• The wavelength, λ = 2.5 m
Find:
• The speed of the wave, v
The speed of a wave of wavelength λ and frequency f is given by,
![v=f\cdot\lambda](https://tex.z-dn.net/?f=v%3Df%5Ccdot%5Clambda)
Substitute the known values and solve,
![v=250Hz\cdot2.5m=625m/s](https://tex.z-dn.net/?f=v%3D250Hz%5Ccdot2.5m%3D625m%2Fs)
Hence, the speed of the wave is 625 m/s.
Answer: The correct answer is True.
Explanation:
Loudness of sound is referred to how soft or loud a sound is for the listener.
This term is measured in a unit known as decibels referred to as dB.
This unit is used to measure the relative intensity of sounds on a scale from zero to 100 dB.
More the value of decibels, it will be uncomfortable for a person to hear that sound.
So Yes, the loudness of sound is measured in decibels.
Answer:
When elements combine, they form molecules. Simply put, a molecule is a group of two or more atoms chemically bonded together. ... Certain molecules are also compounds. A compound is a group of two or more different atoms chemically bonded together.
Answer: ![0.223 m/s^{2}](https://tex.z-dn.net/?f=0.223%20m%2Fs%5E%7B2%7D)
Explanation:
We can solve this with the Law of Universal Gravitation and knowing the acceleration due gravity
of an object above the surface of the planet decreases with the distance (height) of this object from the center of the planet.
Well, according to the law of universal gravitation:
(1)
Where:
is the module of the force exerted between both bodies
is the gravitational constant
is the mass of the Earth
are the mass of each communications satellite
is the distance between the center of the Earth and the satellite
is the radius of the Earth
is the height of the satellite, measured from the Earth's surface
On the other hand, we know according to <u>Newton's 2nd law of motion:</u>
(2)
Combining (1) and (2):
(3)
Isolating
:
(4)
Remembering
:
(5)
Finally: