Beats.
When two sound waves of different frequency approach your ear, the alternating constructive and destructive interference causes the sound to be alternatively soft and loud - a phenomenon which is called "beating" or producing beats. The beat frequency is equal to the absolute value of the difference in frequency of the two waves.
Answer:

Explanation:
The relative velocity can be calculated by means of the difference between vector B minus vector A.

Answer:
6.67 ohm
Explanation:
From the question given above, the following data were obtained:
Resistor 1 (R₁) =20 ohm
Resistor 2 (R₂) = 20 ohm
Resistor 3 (R₃) = 20 ohm
Equivalent Resistance (R) =?
Since the resistors are arranged in parallel connection, the equivalent resistance can be obtained as follow:
1/R = 1/R₁ + 1/R₂ + 1/R₃
1/R = 1/20 + 1/20 + 1/20
1/R = (1 + 1 + 1) / 20
1/R = 3/20
Invert
R = 20/3
R = 6.67 ohm
Therefore, the equivalent resistance is 6.67 ohm.
Answer:
option a.
Explanation:
We can think of an atom as a nucleus (where the protons and neutrons are) and some electrons orbiting it.
We also know that the mass of an electron is a lot smaller than the mass of a proton or the mass of an electron.
So, if all the protons and electrons of an atom are in the nucleus, we know that most of the mass of an atom is in the nucleus of that atom.
Then we define the mass number, which is the total number of protons and neutrons in an atom. Such that the mass of a proton (or a neutron) is almost equal to 1u
Then if we define A as the total number of protons and neutrons, and each one of these weights about 1u
(where u = atomic mass unit)
Then the weight of the nucleus is about A times 1u, or:
A*1u = A atomic mass units.
Then the correct option is:
The mass of the nucleus is approximately EQUAL to the mass number multiplied by __1__ Atomic Mass unit.
option a.
Answer:
10 :)
You have to divide the difference of speed and divide it by the time. So 100-20 would be 80, and if you divide that by 8 it would be 10.
Hope this helps.