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Determining the Focal Length of a Lens Purpose 1. To observe the formation of an image by a converging lens and to determine the focal length (f) of a converging lens using the mirror equation. 2. Test whether the magnification and mirror equation apply to a converging lens. Variables Manipulated: object to lens distance (do) Responding: image to lens distance (di) Controlled: lens focal length (f) Hypothesis 1 1 1 1 The variables will obey the mirror equationππ + ππ = π. If this equation is correct, then a graph of ππ vs 1 ππ should have a slope of _____ (relate this to a physics equation) and an intercept of _____ (relate this to y = mx + b). Show work below Apparatus Procedure Write procedure below Data and Observations do (cm) di (cm) 1/do (cm-1) 1/di (cm-1) Data Analysis Using the y-intercept found from graphical analysis, determine the focal length of the lens. In your response, provide a graph of the reciprocal of the image distance as a function of the reciprocal of the object distance, determine the y-intercept of the graph, and relate the yintercept algebraically to a physics equation. Using the slope of the graph found from graphical analysis, determine the magnification of the image. In your response, determine the slope of the graph and relate the slope algebraically to a physics equation. State all necessary physics concepts and formulas.