Question

The diameter of a tennis ball is 2 cm and the diameter of the softball is 1 cm. About how many times as

great is the surface area of a half of the tennis ball as to the surface area of a half of the softball? If
necessary, round to the nearest whole number.

Answer 1

Explanation:

It is given that,

The diameter of a tennis ball is 2 cm and the diameter of the softball is 1 cm. So, radius of tennis ball is 1 cm and radius of softball is 0.5 cm.

Both balls are in the shape of sphere. Half of the balls will becomes hemisphere. The surface area of hemisphere is given by :

`A=2\pi r^2`

Taking ratio of both balls, i.e.

`(A_1)/(A_2)=(r_1^2)/(r_2^2)`

`(A_t)/(A_s)=(r_t^2)/(r_s^2)\\\\(A_t)/(A_s)=(1^2)/((0.5)^2)\\\\(A_t)/(A_s)=4`

So, the surface area of a half of the tennis ball is 4 times of he surface area of a half of the softball.