A person has a near point of 40 cm and a far point of 1.0 m.When looking through lenses of focal length -1.0 m,what is the nearest an object can be to be seen clearly?
A)29 cm
B)67 cm
C)134 cm
D)140 cm
E)68 cm

Question

A person has a near point of 40 cm and a far point of 1.0 m.When looking through lenses of focal length -1.0 m,what is the nearest an object can be to be seen clearly?
A)29 cm
B)67 cm
C)134 cm
D)140 cm
E)​68 cm

Quizplus · Accepted Answer

The lens formula is 1/f = 1/v - 1/u. Here, f = -1 m, and the far point v = 1 m. Solving for u gives u = 0.67 m or 67 cm.

A Person Has a near Point of 40 Cm and a Far