Define mechanical energy useing the example of the skateboarder on the half-pipe explain how kinetic and potential energy relate to the mechanical energy at diffrent positions

When some one balance skate board on pipe the potential energy is responsible to make it slide beacause of m mass and g gravity and height thus the skate boarder concieves mgh potential energy and moving on pipe with balancing himself using kinetic enrgy ie;1/2 mv^2 and thus gauning speed ..for illustrating well there is a another example the two wheeeler gets balanced while moving instead of standing idle or stationary ie; kinetic energy is responsible for balancing

Alkaline earth metals are found in group 2 of the periodic table.