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
ANSWER: Friction is a force that opposes motion. When two objects are in contact, friction is acts in a direction opposite to the motion of the object.
EXPLANATION: HOPE THIS HELPS.
Answer: B. The trace jumps down 1 division
Explanation:
From the above data, the two signals are combined and adjusted in the middle of the screen. If you switch the signal in channel B from DC to AC, then the screen jumps down 1 division.