Four particles of mass 1kg , 2kg , 3kg and 4kg are placed at the four vertices A , B , C and D of square of side 1m . Find the position of centre of mass of the particle.

Appreciated if self - explained~ ☘

Aplayground slide is 8.80 ft long and makes an angle of 25.0° with the horizontal. a 63.0-kg child, initially at the top, slides all the way down to the bottom of the slide. (a) choosing the bottom of the slide as the reference configuration, what is the system's potential energy when the child is at the top and at the bottom of the slide? what is the change in potential energy as the child slides from the top to the bottom of the slide? (include the sign of the value in your answer.)