Answer:
the frequency of light is

Explanation:
from v = λf
speed of light in air, v = 3.0*10^8ms^-1
1. Double-Replacement reactions
2. Decomposition
3. Combustion
4. Syntesis
5. Single replacement
<h3>Further explanation</h3>
Given
Chemical equations
Required
Type of reaction
Solution
1. 2AgNO₃ + MgCl₂ ⇒ 2AgCl + Mg(NO₃)₂
Double-Replacement reactions. Happens if there is an ion exchange between two ion compounds in the reactant
2. 2KBr⇒2K +Br₂
Decomposition
Single compound breaks down in to 2 or more products
3. C₃H₈ + 5O₂ ⇒ 4H₂O + 3CO₂
Combustion
Hydrocarbon and Oxygen reaction and form water and carbon dioxide
4. NaO + H₂O ⇒ NaOH
Syntesis
2 or more reactants combine to form a single product
5. Zn + CuCl₂ ⇒ZnCl₂ + Cu
Single replacement
One element replaces another element from a compound
Answer:
The tension in the string is 78.73 N.
Explanation:
The tension in the string can be determined from the expression;
v = 
where: v is the speed of the wave in the sting, T is the tension in the string and m is the mass per unit length of the sting.
Given that: v = 16.2 m/s, and m = 0.3 kg/m.
Then;
16.2 = 
Square both sides to have,
= 
T =
x 0.3
= 252.44 x 0.3
= 78.732
T = 78.732 N
The tension in the string is 78.73 N.