Anyone who really good in math please help me
1. A hard candy has a radius of 9 mm. The candy has a spherical soft center with a radius of 6 mm, with a hard shell surrounding it.

What is the volume of the hard shell?
Use 3.14 to approximate pi and round the answer to two decimal places.

_______mm3

2.Which container holds the most?

A.
cylinder with radius 8 in. and height 10 in.

B.
sphere with radius 7 in.

C.
cone with radius 10 in. and height 20 in.

3.What is the volume of a cone that has a radius of 4 cm and a height of 9 cm? Use 3.14 to approximate pi and round the answer to two decimal places if necessary.
_______cm3


Sagot :

A] First you want to work out the volume of both the total candy and the soft shell. The formula for the volume of a sphere is πr cubed x 4/3. The candy has a 9mm radius, so let's substitute that into the equation. π x 9 cubed x 4/3. Nine cubed is, of course, 729, so the volume for the candy is 3052.08mm squared.

Next, the volume of the soft shell. Repeat the earlier steps with the radius of 6mm ( π x 6 cubed x 4/3 ) and you get 904.32mm. Now you substitute that from the total volume: 3052.08-904.32=2147.76mm cubed *units are important*

B] A cylinder is a prism, so first work out the face and multiply by its depth for the area. Area of a circle = πr squared so 3.14 x 64 = 200.97 multiplied by 10 gives you 2009.7 inches cubed. I've already given the steps to working out a spheres volume : 1436.03 cubed inches.
Formula for the volume of a cone: 1/3 x area of base x height Circle base = 314 inches. Volume of cone = 2093.34 cubed inches The answer = the cone aka C.

3] area of a cone is 1/3 x area of base x height Area of circular base = pi x radius squared = 3.14 x 16 = 50.24 1/3 x 50.24 x 9 = 150.72cm cubed. Sorry if this doesn't have proper paragraphs, I've been using the mobile website via tablet, hope I helped.