Locate the image and find its height.

Explanation

`mu_1=1,mu_2=(4)/(3),u=-40cm,R=-20cm,v=?`
`(mu_2)/(v)-(mu_1)/(u)=(mu_2-mu_1)/(R)`
`((4)/(3))/(v)-(1)/(-40)=((4)/(3)-1)/(-20)`
`(4)/(3v)=-(1)/(60)-(1)/(40)=(-2-3)/(120)=-(1)/(24)`
`v=-32`
The magnification
`m=(I)/(O)=(mu_1v)/(mu_2u)`
`(I)/(1)=(1xx(-32))/((4)/(3)xx(-40))`
`l=+0.6cm`
The image is erect.