Check all that apply. the center of gravity of a triangular solid with uniform thickness and density
a. the point at which one can balance the triangle.
b. the point shared by a triangle's altitudes.
c. the centroid.
d. the orthocenter.

Complete these sentences. if a roller coaster train has a potential energy of 1,500 j and a kinetic energy of 500 j as it starts to travel downhill, its total energy isj. once the roller coaster train gets closer to the bottom of the hill, its kinetic energy increases to 1,100 j, and its potential energy decreases to j. when the train reaches the bottom of the track and is traveling along the ground, its kinetic energy isj.