"you have a flat piece of plastic of uniform density ρ in the shape of a right triangle. the legs of the triangle are given as a and b. where is the center of mass of this triangle? using the coordinate system given, enter the coordinates of the center of mass in terms of a and b."

Since the piece of plastic with uniform density is a Right angled triangle ;

For a right angled triangle the centroid and the center of mass is the same. the center of mass can be determined by taking the average value of the three legs of the right angled triangle.

Therefore to actually determine the  location of the center of mass in the triangle, look for  the point of intersection between 1/3 height and 1/3 base length of the triangle.

Hence we can conclude that The center of mass of the triangle is located at the point where ; 1/3 base length and 1/3 height of the triangle intersects and The coordinates of the center of mass  is ; ( a/3 , b/3 ).

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the order for strong to weak forces such as

strong nuclear force → electromegnetic force → weak nuclear force → gravitational force

the fundamental forces are those forces that act between to objects or element to make interactions. there are four types of fundamental forces such as strong and weak nuclear forces (due to protons and electrons), electromagnetic force (due to the motion of electrons) and gravitational force (due to orbital movement of the planet). if these forces are arranged on the basis of their maximum strength then the order is

strong nuclear force → electromegnetic force → weak nuclear force → gravitational force

54 degrees incident angle = reflected angle

angle is from normal turned to line of ray