A cylindrical container has a diameter of 14cm and a height of 20cm and is full of water. A student pours the water into mother's cylinder of diameter of 20cm How deep is the water in the second cylinder.

1 answer

Let's call the first cylinder Cylinder 1 and the second cylinder Cylinder 2.

We can start by finding the volume of water in Cylinder 1. The formula for the volume of a cylinder is V = πr^2h, where r is the radius and h is the height.

Since the diameter of Cylinder 1 is 14cm, the radius is half that, or 7cm. And the height is 20cm. So, the volume of water in Cylinder 1 is:

V1 = π(7cm)^2(20cm) = 2,940π cm^3

Now, we can use the formula for the volume of a cylinder again to find the height of the water in Cylinder 2. We know the radius of Cylinder 2 is 10cm (half of the diameter of 20cm), but we don't yet know the height of the water in Cylinder 2. Let's call that h2.

We can set up an equation to solve for h2. The volume of water in Cylinder 2 must be equal to the volume of water in Cylinder 1:

V2 = V1

π(10cm)^2h2 = 2,940π cm^3

Simplifying:

h2 = 2,940/100 = 29.4 cm

So the height of the water in Cylinder 2 is 29.4cm.