The 2 decomposition reactions are:
B. 
(s) -->
(s) +
(g)
C.
(g) -->
(g) +
(g)
Explanation:
Step 1:
A decomposition reaction is one in which a single compound breaks down into two or more products.
Step 2:
Let us examine each reaction if it satisfies the above rule.
A. 2 LiOH +
--->
+ 
In this reaction we have 2 reactants giving 2 products. Hence this is not a decomposition reaction.
B.
--->
+ 
In this reaction a single reactant potassium carbonate gives rise to 2 products Potassium Oxide and carbon-di-oxide. Hence this is a decomposition reaction
C.
--->
+ 
In this reaction a single reactant sulfur tri-oxide gives rise to 2 products sulfur di-oxide and oxygen. Hence this is a decomposition reaction.
D.
+
---> 
In this reaction 2 reactants sodium and chlorine gives rise to a single product sodium chloride. Hence this is not a decomposition reaction.
Step 3:
Answer:
The 2 decomposition reactions are:
B.
(s) --->
(s) +
(g)
C.
--->
+ 
S = ut + 0.5at^2
<span>10 = 0 + 0.5(9.81)t^2 {and if g = 10 then t^2 = 2 so t ~1.414} </span>
<span>t^2 ~ 2.04 </span>
<span>t ~ 1.43 seconds</span>
Since momentum is a vector quantity, take any direction as positive and other as negative. Answer won't change.
Answer:
The tension of the string is 41.876 N
Explanation:
Given;
length of the string, L = 2.11 m
mass of the string, m = 19.5 g = 0.0195 kg
frequency of the wave, f = 440 Hz
wavelength, λ = 15.3 cm = 0.153 m
The velocity of the wave is given by;
v = fλ
v = 440 x 0.153
v = 67.32 m/s
Also the velocity of the wave is given by

where;
μ is mass per unit length = 0.0195 / 2.11 = 0.00924 kg/m
T is the tension of the string
T = v²μ
T = (67.32)²(0.00924)
T = 41.876 N
Therefore, the tension of the string is 41.876 N