The answer is B. A guitar generally produces sound waves that propagate when the strings are strummed. The strings are displaced through the vibrations caused by contact of the hand and the guitar. You will also notice the vibrations by looking closely to the string. Wave particles continuously collide with each other to make a sustaining or prolonging sound.
Answer
× 10²³ molecules are in 41.8 g of sulfuric acid
Explanation
The first step is to convert 41.8 g of sulfuric acid to moles by dividing the mass of sulfuric acid by its molar mass.
Molar mass of sulfuric acid, H₂SO₄ = 98.079 g/mol

Finally, convert the moles of sulfuric acid to molecules using Avogadro's number.
Conversion factor: 1 mole of any substance = 6.022 × 10²³ molecules.
Therefore, 0.426187053 moles of sulfuric acid is equal

Thus, 2.57 × 10²³ molecules are in 41.8 g of sulfuric acid.
Answer:
The mass of water
= 39.18 gm
Explanation:
Mass of iron
= 32.5 gm
Initial temperature of iron
= 22.4°c = 295.4 K
Specific heat of iron
= 0.448 
Mass of water =
Specific heat of water 
Initial temperature of water
= 336 K
Final temperature after equilibrium
= 59.7°c = 332.7 K
When iron rod is submerged into water then
Heat lost by water = Heat gain by iron rod
(
-
) =
(
-
)
Put all the values in above formula we get
× 4.2 × ( 336 - 332.7 ) = 32.5 × 0.448 × ( 332.7 - 295.4 )
= 39.18 gm
Therefore the mass of water
= 39.18 gm