To solve this problem it is necessary to apply the concepts of Work. Work is understood as the force applied to travel a determined distance, in this case the height. The force in turn can be expressed by Newton's second law as the ratio between mass and gravity, as well

Where,
m = mass
h = height
g = Gravitational constant
When it ascends to the second floor it has traveled the energy necessary to climb a height, under this logic, until the 4 floor has traveled 3 times the height h of each of the floors therefore

Replacing in our equation we have to

The correct answer is 4.
They travel like waves. Just throw rock at lake you will see wave. When it bumps to barrier barrier reflects some part of it . Not like a line lika a wave
The resultant of the given forces is; 6√2 N
<h3>How to find the resultant of forces</h3>
We are given the forces as;
10 N along the x-axis which is +10 N in the x-direction
6 N along the y-axis which is +6N in the y-direction
4 N along the negative x-axis which is -4N
Thus;
Resultant force in the x-direction is; 10 - 4 = 6N
Resultant force in the y-direction is; 6N
Thus;
Total resultant force = √(6² + 6²)
Total resultant force = 6√2 N
Read more about finding resultant of a force at; brainly.com/question/14626208