Question:
If y varies inversely with the square of r, what is the constant of proportionality when y =10 and r = 5?
Answer:
The constant of proportionality is 250
Solution:
Given that,
y varies inversely with the square of r
Which means,
[tex]y \propto \frac{1}{r^2}\\\\y = k \times \frac{1}{r^2}[/tex]
Where, "k" is constant of proportionality
Subtitute y = 10 and r = 5
[tex]10 = k \times \frac{1}{5^2}\\\\10 = k \times \frac{1}{25}\\\\k = 10 \times 25\\\\k = 250[/tex]
Thus the constant of proportionality is 250
