No. Mechanical energy is not conserved. There's quite a bit of friction on the slide. So some of the potential energy is lost to heat on the way down, and the child arrives at the bottom with hot pants and less kinetic energy than you might expect.
Answer:54.70 N
Explanation:
Given
Gauge Pressure of 
i.e. 
Effective area 
initial Pressure
Gauge Pressure 
Force creates a pressure of 
which will be equal to Gauge Pressure
Answer:
C
Explanation:
For a uniformly distributed mass, the center of gravity is also the geometric center. For this shape, the center is at point C.
