Answer: The ratio of atoms of potassium to ratio of atoms of oxygen is 4:2
Explanation:
According to the law of conservation of mass, mass can neither be created nor be destroyed, and remains conserved. The mass of products must be same as that of the reactants.
Thus the number of atoms of each element must be same on both sides of the equation so as to keep the mass same and thus balanced chemical equations are written.
K exists as atoms and oxygen exist as molecule which consists of 2 atoms. The ratio of number of atoms on both sides of the reaction are same and thus the ratio of atoms of potassium to ratio of atoms of oxygen is 4:2.
Answer: 
Explanation:
Given
Radioactive material is found to decrease 40% of its original value in 
Sample at any time is given by
where, 
Put values
Taking natural logarithm both side
The energy of the wave will decrease.
The energy of a wave is given as
E = h f
where E = energy of waver
h = plank's constant
f = frequency of the wave.
From the formula , we see that the energy of the wave is directly proportional to the frequency of the wave. hence as the frequency of the wave decrease, the energy of the wave will decrease.
Answer: 4.86
Explanation:
sphere moment of Inertia Iₑ = (2/5)mrₑ²
Let the sphere of radius 1.59 cm be x
Let the spherical shell of radius 7.72 cm be y, so that
Iₑ(x) = 2/5 * m * 1.59²
Iₑ(x) = 2/5 * m * 2.5281
Iₑ(x) = 1.011m
Iₑ(y) = 2/5 * m * 7.72²
Iₑ(y) = 2/5 * m * 59.5984
Iₑ(y) = 23.84m
Also, the angular speed of the sphere's would be ωₑ(x) and ωₑ(y)
total k.e = rotational k.e + linear k.e
for sphere = ½Iₑωₑ² + ½mωₑ²rₑ²
For sphere x
{ωₑ²[ 1.011 + 1.59²]} =
ωₑ²(1.011 + 2.5281) =
ωₑ²(3.5391)
For sphere y
{ωₑ²[ 23.84 + 7.72²]} =
ωₑ²(23.84 + 59.5984) =
ωₑ²(83.4384)
If the ratio of x/y = 1, then
ωₑ(x)²(3.5391) / ωₑ(y)²(83.4384) = 1
ωₑ(x)²(3.5391) = ωₑ(y)²(83.4384)
[ωₔ(x)/ωₑ(y)]² = [83.4384] / [3.5391] ~= 23.5762
[ωₔ(x)/ωₑ(y)] = √(23.5762)
[ωₔ(x)/ωₑ(y)] = 4.86
