1) Einstein's equation revolutionized the way we perceive the universe. The equation E = mc^2

Draw the FBDs for the following the system is which there is a childand the chair. Draw it in a simplied version with explanations.

I am trying to find a Direction Cosine Matrix (DCM) for the Euler angle body 1-2-3 sequence. I tried making my own function and using the MATLAB function, but the result is a matrix that is transpose of each other. I mean that transpose(EA123toDCM) = E123toDCM. Why is that? Also, for the E123toDCM line, I am using the sequence 'ZYX'. Is that correct or should it be 'XYZ'? I know that that for a DCM of sequence 1-2-3 = R3(theta1)*R2(theta2)*R1(theta3). Is ZYX sequence the same as a 1-2-3 sequence?   EA = [pi/3; -pi/4; -pi/6];EA123toDCM = EA123DCM(EA) E123toDCM = angle2dcm(EA(1,1), EA(2,1), EA(3,1), 'ZYX')   function [R] = EA123DCM(EA)     theta1 = EA(1,1);    theta2 = EA(2,1);    theta3 = EA(3,1);            R1 = @(a)[1    0      0    ;              0  cos(a) -sin(a);              0  sin(a) cos(a)];              R2 = @(a)[cos(a)  0 sin(a) ;                0     1   0    ;              -sin(a) 0 cos(a)];              R3 = @(a)[ cos(a) -sin(a) 0;               sin(a) cos(a)  0;…

Please don't provide handwritten solution ......