Physics

Problem

A student attempted to locate the image formed by a convex mirror of focal length

15\,\text{cm}

for an object placed

10\,\text{cm}

in front of the mirror. The student wrote: “Taking

u=+10\,\text{cm}

and

f=+15\,\text{cm}

in the mirror equation, I obtain

v=−30\,\text{cm}

.” (a) Point out the sign error(s) in the student’s choice of quantities. (b) Determine the correct value of the image distance

v

and the magnification

m