The volume of a cylinder is 1470pi cmcubed. The height of the cylinder is 30 cm. What is the radius of the​ cylinder?

1 answer

To find the radius of a cylinder given its volume and height, we can use the formula for the volume of a cylinder:

\[ V = \pi r^2 h \]

where \( V \) is the volume, \( r \) is the radius, and \( h \) is the height.

Given:

  • \( V = 1470\pi \) cm³
  • \( h = 30 \) cm

We can substitute these values into the formula:

\[ 1470\pi = \pi r^2 (30) \]

Next, we can divide both sides by \( \pi \) (assuming \( \pi \) is not zero):

\[ 1470 = r^2 (30) \]

Now, we can solve for \( r^2 \) by dividing both sides by 30:

\[ r^2 = \frac{1470}{30} \]

Calculating the right-hand side:

\[ r^2 = 49 \]

Now, to find \( r \), we take the square root of both sides:

\[ r = \sqrt{49} = 7 \text{ cm} \]

Thus, the radius of the cylinder is \( \boxed{7} \) cm.