Explanation:
Let me know if you have questions
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
1. If we increase the distance to twice it's original value, the light intensity is reduced by one-fourth, the light intensity would be:
I0/4
2. rms magnetic field is inversely proportional to distance, so the new rms magnetic field would be:
B0/2
3. average energy density is inversely proportional to the square of the distance, so the new average energy density is:
E0/4
<span>In order for
an object to accelerate, a <u>force</u> must be applied. It follows Newton’s second
law of motion where it states that a body at rest remains at rest unless a
force is acted upon it. When you move an object, you are exerting a force onto
it. By exerting a force on the object, you are actually displacing it from its
initial position. You cannot apply force to the object without altering its
position. Keep in mind that when you exert work, you are exerting energy too. </span>