Question

You are in a nightmare in which you are in a slow-moving truck being chased by a dinosaur in that infamous scene from "Jurassic Park". However, you did have the presence of mind to have installed a flat rear-view mirror so as to get an accurate impression of the distance of things chasing you. This mirror is 150.0 mm tall and is 0.7000 m from your eyes when you are driving. If the image of the dinosaur is just filling the mirror vertically, what is the distance of the dinosaur from your mirror (in meters) if the dinosaur is, in fact, 15.00 m tall.

Thanks for help

Answer 1

The mirror is convex in nature. We need to find the "OBJECT DISTANCE or o" in this question. For this question we have following terms- Object height= 15 m Image distance= 0.7 m Image height= 150 mm= 0.15 m.

We have taken the height of the mirror as "IMAGE HEIGHT" because the question says the dinosaur is filling the mirror vertically.

To find "OBJECT DISTANCE" we will be using formula of magnification, i.e.

m = image distance/ object distance = image height/ object heigt. Putting the values, we get

0.7/ o = 0.15/ 15, o= 0.7*15 / 0.15= 70 m from the mirror.