Because the sound waves are being observed by the people that are there and it is not empty as in an empty place the sound waves will come back to you.
Answer:
Explanation:
ΔE = Δm × c^2
where,
ΔE = change in energy released with respect to change in mass
= 1.554 × 10^3 kJ
= 1.554 × 10^6 J
Δm = change in mass
c = the speed of light.
= 3 × 10^8 m/s
Equation of the reaction:
2H2 + O2 --> 2H2O
Mass change in this process, Δm = 1.554 × 10^6/(3 × 10^8)^2
= 1.727 × 10^-11 kg
The change in mass calculated from Einstein equation is small that its effect on formation of product will be negligible. Hence, law of conservation of mass holds correct for chemical reactions.