Radius of CurvatureRadius of CurvatureLab ReportLab Report

Daniela MarinelliDaniela MarinelliEmily ShorrockEmily ShorrockEmmett KeyserlingkEmmett KeyserlingkWilliam MacDaddyWilliam MacDaddy

PurposePurpose

To determine the To determine the principal principal characteristics of a characteristics of a convex mirror & to convex mirror & to find the mathematical find the mathematical relationship between relationship between the radius of the radius of curvature and the curvature and the focal length of the focal length of the mirror.mirror.

MaterialsMaterials

PaperPaper PencilPencil RulerRuler Ray Box (5 slit)Ray Box (5 slit) Convex mirrorConvex mirror

Procedure – Finding Focal Procedure – Finding Focal PointPoint

Shine 5 parallel light rays at the Shine 5 parallel light rays at the convex mirror. Using a ruler, trace the convex mirror. Using a ruler, trace the incident and reflected rays.incident and reflected rays.

Back-trace the reflected rays – the Back-trace the reflected rays – the point where they meet is the mirror’s point where they meet is the mirror’s focal point. focal point.

f

Procedure – Finding Focal Procedure – Finding Focal PointPoint

Procedure – Finding Centre of Procedure – Finding Centre of

CurvatureCurvature

Draw the full circle of the mirror.Draw the full circle of the mirror. Measure along the principal axis to Measure along the principal axis to

find the exact centre of the circle – this find the exact centre of the circle – this is the mirror’s centre of curvature.is the mirror’s centre of curvature.

Measure the distance from the centre Measure the distance from the centre of curvature to the mirror – this is your of curvature to the mirror – this is your radius of curvature.radius of curvature.

Procedure – Finding Centre of Procedure – Finding Centre of CurvatureCurvature

??

Compare your results. What do Compare your results. What do you notice about the focal length you notice about the focal length and  the radius of curvature? and  the radius of curvature?

Procedure – Characteristics of a Procedure – Characteristics of a convex mirrorconvex mirror

Using ray diagrams, experiment Using ray diagrams, experiment with different object distances with different object distances and observe what images they and observe what images they form. Are they upright, inverted, form. Are they upright, inverted, virtual or real?virtual or real?

AnalysisAnalysis

Images produced by convex Images produced by convex mirrors have multiple mirrors have multiple characteristics. In a convex characteristics. In a convex mirror, the image will be virtual, mirror, the image will be virtual, upright, reduced in size (i.e., upright, reduced in size (i.e., smaller than the object), and will smaller than the object), and will be located behind the mirror.be located behind the mirror.

AnalysisAnalysis

A convex mirror is also known as a A convex mirror is also known as a diverging mirror. This is due to the diverging mirror. This is due to the way incident light rays coming from way incident light rays coming from the same point diverge.the same point diverge.

Convex mirrors are sometimes used Convex mirrors are sometimes used as surveillance devices in as surveillance devices in convenience stores and other convenience stores and other places which are weary of criminalsplaces which are weary of criminals

ConclusionConclusion

In an example conducted in the results In an example conducted in the results section, it is clearly shown that when section, it is clearly shown that when the radius of curvature is 5cm, the the radius of curvature is 5cm, the focal length is 2.5cm. This supports focal length is 2.5cm. This supports the formula that f=1/2r.the formula that f=1/2r.

In a convex mirror, the image will be In a convex mirror, the image will be virtual, upright, reduced in size (i.e., virtual, upright, reduced in size (i.e., smaller than the object), and will be smaller than the object), and will be located behind the mirror.located behind the mirror.

The variation in object distance affects The variation in object distance affects the image distance and size.the image distance and size.

FINFIN