Question

a spray can is usedto paint a wall .the thickness of the paint on the wall is t.the distance of the spray can from the wall is d. t is inversly proportional to the square of d. t=0.2 when d=8.find t when d=10

Answer 1

t = 0.128

Explanation:

Proportionality

We are given the following proportionality rule: t is inversely proportional to the square of d. This can be written as:

`\displaystyle t=(k)/(d^2)`

Where k is the constant of proportionality. It can be found by using the condition: t=0.2 when d=8. Substituting:

`\displaystyle 0.2=(k)/(8^2)`

`\displaystyle 0.2=(k)/(64)`

Solving for k:

k=12.8

The equation is:

`\displaystyle t=(12.8)/(d^2)`

When d=10:

`\displaystyle t=(12.8)/(10^2)`

t = 0.128