Question

***HELP FOR POINTS***

If a concave mirror has a focal length of 10.0 cm, what is the image distance of a pen that is placed upright 5.00 cm from the mirror?

Answer 1

According to the the Gaussian mirror equation,
\[\frac{ 1 }{ F }=\frac{ 1 }{ O }+\frac{ 1 }{ I }\]
where F=focal lenght
O= object distance
I=image distance
therefore,
\[\frac{ 1 }{ I }=\frac{ 1 }{ F }-\frac{ 1 }{ O }\]
\[\frac{ 1 }{ I }=\frac{ 1 }{ 10 }-\frac{ 1 }{ 5 }\]
\[\frac{ 1 }{ I }= -0.1\]
\[I= -10\]
The will be at a distance of 10cm inside the mirror i.e. at -10cm
And it will be virtual, upright and magnified.