Answer:
A=
Explanation:
We have given power =40 W but only 10% of this power is used so actual power 
We know that from Stefan's law 
where 
is Boltzmann constant which value is 
So 
A=
Answer:
The answer to your question are A and C
Explanation:
Quantitative data are quantities, something that we get after measuring something.
A. Measuring the rate of gas production from a chemical. This example is a quantitative measure, because we are measuring the rate.
B. Describing the clarity of water in a sample If we are describing something, means that we are not measuring anything, so this is not a quantitative measure.
C. Calculating the energy released from an electrochemical reaction If we are not measuring but we are using the data somebody else got to calculate energy, them this is a quantitative data.
The answer would be a=5 m/s^2
I hope this helps you, have a great day!
You didn't mention it, but the trumpeter herself has to be standing still.
<span>Person C, the one running towards the trumpeter, hears a pitch
that is higher than B-flat. (A)
Person B, the one running away from the trumpeter, hears a pitch
that is lower than B-flat.
Person D, the one standing still the whole time, hears the B-flat.</span>
