Question 20 • Physics
Use the mirror equation, 1/f = 1/dₒ + 1/dᵢ, with f = −4.5 cm and dₒ = 9.0 cm. Then 1/dᵢ = −1/4.5 − 1/9 = −1/3, so dᵢ = −3 cm. The negative sign means the image is virtual and behind the mirror, so the answer is negative 3 centimeters.
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