A concave mirror has a radius of curvature of $60.0 \mathrm{~cm}$. Calculate the image position and magnification of an object placed in front of the mirror (a) at a distance of $90.0 \mathrm{~cm}$ and $(\mathrm{b})$ at a distance of $20.0 \mathrm{~cm} .$ (c) In each case, draw ray diagrams to obtain the image characteristics.