# Imagine you have a gun which shoots peanut butter .you want to spread peanut butter on some bread so you move the gun 1 m away from the bread and fire. Unfortunately the peanut butter on the bread...

Imagine you have a gun which shoots peanut butter .you want to spread peanut butter on some bread so you move the gun 1 m away from the bread and fire. Unfortunately the peanut butter on the bread is twice as thick as you ideally want it to be. So you move the gun back to 2 m from the bread and fire again. Will you have gotten the perfect thickness of peanut butter? Why or why not?

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### 1 Answer

The distance from where the peanut butter gun is fired, and thickness of the butter that is spread is related by inverse square law:

`d prop 1/r^2`

Therefore, if you are twice as far away from the butter sccop while firing, the butter should spread one-fourth as thick.

If you are to spread butter half as thick, you need to fire from `sqrt2*1m` , i.e. from a distance of 1.414 m to get the required thickness of butter.