Final answer:
To find the value of y when R is 10, we first determine the constant of proportionality (k) using the given values, and then apply it in the direct variation equation. The calculation shows that when R is 10, the value of y is 20.
Step-by-step explanation:
You have stated that y varies directly as the square of R. This means that we can write a direct variation equation in the form of y = k * R², where k is the constant of proportionality. Given that y is 5 when R is 5, we first calculate the constant of proportionality using these values.
To find k, we plug in 5 for both y and R:
5 = k * 5²
5 = k * 25
k = 5 / 25
k = 1/5
Now that we have determined the constant k, we can use it to find y when R is 10. We plug in these values into the direct variation equation:
y = (1/5) * 10²
y = (1/5) * 100
y = 20
Therefore, when R is 10, y is 20.