You would know a decomposition reaction occurred if the reactants separated. For example from AB → A+B.
Now if you look at your options only 1 works out for that equation. Letter A.
From the compound K2CO3 it split up to K2O +CO2
It cannot be letter B because synthesis/combination occurred. The same goes for letter C. Letter D, single displacement occurred.
Again, the answer is A.
Answer:
0.3659
Explanation:
The power (p) is given as:
P = AeσT⁴
where,
A =Area
e = transmittivity
σ = Stefan-boltzmann constant
T = Temperature
since both the bulbs radiate same power
P₁ = P₂
Where, 1 denotes the bulb 1
2 denotes the bulb 2
thus,
A₁e₁σT₁⁴ = A₂e₂σT₂⁴
Now e₁=e₂
⇒A₁T₁⁴ = A₂T₂⁴
or

substituting the values in the above question we get

or
=0.3659
They are both in motion because an object is not at rest, but moving so slow it could be at rest. A car going at the same constant velocity is neither speeding up or slowing down, an object "at rest" is also moving at a constant rate, not speeding up or slowing done.
Answer:
The carriage has the energy, W = 2469.6 J
Explanation:
Given data,
The height of the hill, h = 21 m
The carriage with the baby weighs, m = 12 kg
The energy possessed by the body due to its position is the potential energy,
<em>W = P.E = mgh joules</em>
Substituting the values,
W = 12 x 9.8 x 21
= 2469.6 J
Hence, the carriage has the energy, W = 2469.6 J
<span>The record of an earthquake obtained from a seismic instrument is a </span>
SEISMOGRAM