Answer: 4.17m
Explanation:
The observer at C will hear a sound on no sound upon whether the interference is constructive or destructive.
If the listeners hears sounds it is caled constructive interference but if he hears no sound its called destructive interference.
So
d2 - d1 = (n *lamba)/ 2
Where n=1,3,5
lamda=v/f =349/62.8
lamda=5.56m
d2= d1 + nlamda/2
d2= 1 + 5.56/2
d2= 3.78m
X'= 1 cos 60= 0.5m
Y= 1 sin60= 0.866m
X"^2 + Y^2 =d2^2
X" =√(y^2 - d2^2)
X"=√(3.78^2 - 0.886^2)
X"= 3.67m
So therefore the closest that speaker A can be to speaker B so the listener does not hear any sound is X' + X"= 0.5 + 3.67
4.17m
Friction can be useful when you trying to stop a car, also it can be useful in energy losses, increase wear and tear and produces heat
Answer:
a)
, b) 
Explanation:
a) The maximum possible acceleration that the truck can give to the SUV is:


b) The equation of equilibrium for the truck is:

The force of the SUV's bumper on the truck's bumper is:

Sodium sulfide formula is Na₂S.
Na is a group 1 element, it has one valence electron therefore it is ready to give that valence electron and form an ionic bond. Once it gives out the electron it becomes a positive ion - Na⁺
sulfur is a group 6 element, has 6 electrons its outer shell and needs to gain 2 more electrons to become stable. Once it gains 2 electrons it becomes a negative ion - S²⁻.
Since Na only gives out 1 electron, S²⁻ ion needs to take in 2 electrons, therefore forms an ionic compound with 2 Na⁺ ions.
decomposition of Na₂S is as follows;
Na₂S(s) --> 2Na⁺(aq) + S²⁻ (aq)
CADB are the answer
Can you please give me the brainest one