Exercise 31 Page 213

To find the length of the image seen through the magnifying glass, we will use the fact that the scale factor k can be calculated by dividing the actual length by the image length. k= image lengthactual length We know that the magnifying glass makes an image that is 5 times the object's actual size. Therefore, the scale factor is k=5. From the picture of the emperor moth, we can see that its length is 60mm. We will use these values and the formula to find the image length.

k=image length/actual length

SubstituteII

actual length= 60, k= 5

5=image length/60

MultEqn

LHS * 60=RHS* 60

5*60 = image length

Multiply

Multiply

300 = image length

RearrangeEqn

Rearrange equation

image length = 300

Therefore, the length of the emperor moth seen through the magnifying glass is 300 millimeters.