A concave mirror forms real images with magnifications -2 and -3 at two object positions. If those positions are 10 cm apart, |f| is:
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A concave mirror forms real images with magnifications −2 and −3 at two object positions. If those positions are 10 cm apart, |f| is:

G1 Physics · Accepted Answer

u(M)=f(1+1/M). Difference=f[(1+1/2)−(1+1/3)]=f/6=10, so f=60 cm.