<span>An imaginary line perpendicular to a reflecting surface is called "a normal" (principle line)
So, Your Answer would be Option B
Hope this helps!</span>
Answer:
Heating 100 g of water from 10◦C to 50◦C
Explanation:
m₁ ΔT₁ = 2000
m₂ ΔT₂ = 300
m₃ ΔT₃ = 4000
m₄ ΔT₄ = 70
Physical property, that means that it is not transpaerent, and can touch
To solve the exercise it is necessary to take into account the definition of speed as a function of distance and time, and the speed of air in the sound, as well

Where,
V= Velocity
d= distance
t = time
Re-arrange the equation to find the distance we have,
d=vt
Replacing with our values


It is understood that the sound comes and goes across the entire lake therefore, the length of the lake is half the distance found, that is



Therefore the length of the lake is 634,55m