How many times smaller is the surface area
of a sphere if the radius is multiplied by 1/4?
times smaller



Answer :

To find out how many times smaller the surface area of a sphere becomes when its radius is multiplied by 1/4, let's start with the formula for the surface area of a sphere, which is: \[ A = 4 \pi r^2 \] Now let's consider a sphere with an initial radius \(r_1\). Its surface area would be: \[ A_1 = 4 \pi r_1^2 \] If we then multiply the radius by 1/4, we get a new radius \(r_2 = \frac{1}{4} r_1\). The surface area of the sphere with this new radius is: \[ A_2 = 4 \pi r_2^2 = 4 \pi \left(\frac{1}{4} r_1\right)^2 \] Now we simplify \(A_2\) by squaring the new radius: \[ A_2 = 4 \pi \left(\frac{1}{4}^2 r_1^2\right) = 4 \pi \left(\frac{1}{16} r_1^2\right) \] \[ A_2 = \frac{4 \pi r_1^2}{16} \] \[ A_2 = \frac{4 \pi r_1^2}{4 \cdot 4} \] \[ A_2 = \frac{1}{4} \cdot \frac{4 \pi r_1^2}{4} \] \[ A_2 = \frac{1}{4} \cdot \pi r_1^2 \] Notice that \(A_2\) is exactly 1/16 of \(A_1\) because when you square (1/4), you get (1/16). \[ A_2 = \frac{A_1}{16} \] This means the surface area of the sphere when the radius is multiplied by 1/4 is 16 times smaller than the original surface area. So the answer is that the surface area of the sphere is 16 times smaller when the radius is multiplied by 1/4.