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 at distances of (a) 90.0 $\mathrm{cm}$ and $(\mathrm{b}) 20.0 \mathrm{cm} .$ (c) Draw ray diagrams to obtain the image characteristics in each case.