If the cylinder were dilated using a scale factor of 4, what would be the new surface area? The formula for the surface area of a cylinder

is SA = 2arh + 27p2
(1 point)
О 5,888 т ст?
• 368т cm?
О 1, 472т ст?
• 23т cm?

3 answers

To find the new surface area of a cylinder after a dilation with a scale factor of 4, we need to understand how the surface area of a 3D object scales with its linear dimensions.

When a cylinder (or any 3D shape) is dilated by a scale factor \( k \), the new surface area \( SA' \) can be found using the following relationship:

\[ SA' = k^2 \cdot SA \]

where \( SA \) is the original surface area, and \( k \) is the scale factor.

Let's start by recalling the formula for the surface area of a cylinder:

\[ SA = 2\pi rh + 2\pi r^2 \]

This formula can be interpreted as the lateral surface area \( (2\pi rh) \) plus the area of the two bases \( (2\pi r^2) \).

Now, setting the scale factor:

Given that the scale factor \( k = 4 \), we can square this value:

\[ k^2 = 4^2 = 16 \]

This means the new surface area will be:

\[ SA' = 16 \cdot SA \]

Thus, the new surface area is 16 times the original surface area.

If you have the original surface area \( SA \), you can multiply it by 16 to find the new surface area. However, since the original surface area is not provided, we can only conclude that the new surface area will be 16 times the original value.

In the answer options provided, we cannot directly pick a value without knowing the original surface area. If one of those options represents \( SA \) and multiplying by 16 gives one of the choices, that would be the new surface area.

Please provide the original surface area of the cylinder so we can accurately calculate the new surface area.

8 cm
15cm

Great! Now that we have the dimensions of the cylinder, we can calculate the original surface area using the following formula:

\[ SA = 2\pi rh + 2\pi r^2 \]

where:

  • \( r = 8 \) cm (the radius)
  • \( h = 15 \) cm (the height)

Step 1: Calculate the Original Surface Area

  1. Calculate the lateral surface area: \[ 2\pi rh = 2\pi (8 , \text{cm})(15 , \text{cm}) = 240\pi , \text{cm}^2 \]

  2. Calculate the area of the two bases: \[ 2\pi r^2 = 2\pi (8 , \text{cm})^2 = 2\pi (64 , \text{cm}^2) = 128\pi , \text{cm}^2 \]

  3. Now, add both components together: \[ SA = 240\pi + 128\pi = 368\pi , \text{cm}^2 \]

Step 2: Calculate the New Surface Area After Dilation by a Scale Factor of 4

Since we know that the new surface area will be multiplied by \( k^2 \) (where \( k = 4 \)): \[ SA' = 16 \cdot SA \]

  1. Substitute the original surface area: \[ SA' = 16 \cdot (368\pi) , \text{cm}^2 = 5888\pi , \text{cm}^2 \]

Step 3: Approximate the New Surface Area

Using \( \pi \approx 3.14 \): \[ SA' \approx 5888 \cdot 3.14 \approx 18496.32 , \text{cm}^2 \]

Step 4: Return to the Choices Provided

Since the options provided were formatted differently:

  • \( 5,888 , \text{cm}^2 \)
  • \( 368 , \text{cm}^2 \)
  • \( 1,472 , \text{cm}^2 \)
  • \( 23 , \text{cm}^2 \)

The closest option that represents the appropriate result of the calculation is:

New Surface Area: 5,888 cm² (after multiplying by 16).

So, the answer is 5,888 cm².