Hi. I'm not sure how to picture it on the x-y-axis. I found this in the text book: If i have a plate bounce by 0<= x <=2 and 0<= y <= 3. and the density is constant. i'm looking for two integrals that corresponding to stirps in the x-direction and y-direction. let say the density is 5gm/cm^2 then to integral should be finding the centre of mass right?? and using the center of mass how do i find the total area if i dont know the radius?? correct me if i'm wrong, isn't the centre of mass will be close to the x-axis then y-axis due to its momentum? sorry i'm not really good in physic its hard to get my head around combining physic and cal together.