Distance between the object and the lens

[Libra_girl]

Homework Statement

A diverging lens of 6 mm focal length produces an image of magnification m = 1/2. What
is the distance between the object and the lens?

 

[tiny-tim]

Welcome to PF!

Homework Statement

A diverging lens of 6 mm focal length produces an image of magnification m = 1/2. What
is the distance between the object and the lens?

Hi Libra_girl ! Welcome to PF!

Hint: what equations do you know that relate the size of the object to the size of the image?

 

[Libra_girl]

Hi Libra_girl ! Welcome to PF!

Hint: what equations do you know that relate the size of the object to the size of the image?

Is it the equation: do/di = m or 1/do + 1/di = 1/f ?

 

[tiny-tim]

Is it the equation: do/di = m or 1/do + 1/di = 1/f ?

Both equations!

Except isn't it m = -di/do?

 

[Libra_girl]

Both equations!

Except isn't it m = -di/do?

yeah it is sorry

 

[Libra_girl]

yeah it is sorry

Both equations!

Except isn't it m = -di/do?

Ok so I know f and I know m, now I am solving for do, but I don't know the di?

 

[alphysicist]

Hi Libra girl,

You now have two equations in two unknowns. You can solve the magnification formula for one of the variables and plug it into the other formula. What does that give?