Wednesday

July 23, 2014

July 23, 2014

Posted by **StephanieNZ** on Sunday, March 21, 2010 at 12:58am.

V=4/3 pie r cubed.

Use the formula, and show your workings, to find out what happens to the volume of a sphere if r is halved and r is trippled?

Please help as this has just completly lost me, i end up with

V = 4/3 Pie r cubed / eight .....for half of r.

- Algebra -
**Reiny**, Sunday, March 21, 2010 at 8:19amYou were correct,

when you cut the radius in half, the volume will be 1/8 of the original.

When you triple the radius, the new volume will be 27 times that of the original.

Look at what happens when we substitute the new radius for r

sub in 3r for the radius

V = (4/3)π(3r)^3

= (4/3)π)(27)r^3

= 27 * (4/3)πr^3

Notice that the volume changes by the cube of the scaling factor,

taking 1/2 ----> (1/2)^3 = 1/8

**Related Questions**

algebra II - A formula for the volume of a sphere is V=4/3 pie r^2. If the ...

algebra - The volume of a sphere is given by V=4/3pie cubed. What happens to the...

10th grade - The volume of a small sphere is 36 pie cm cubed. The volume of a ...

algebra - what is the volume of a sphere with radius r is given by the formula v...

Calculus - Hi there i am having some problems trying to do my calculus homework...

Algebra I - volume of a basketball is 448.9 cubic inches. with the formula V=4/...

physics.pls help - The volume of a cylinder is defined by the formula V=pie R ...

algebra - The volume of a sphere is given by V(r) = 4/3*pi*r3. Find the volume ...

spheres - Find the Volume of a hemisphere with a diameter of 17 cm. Use pi = 3....

calculus *improper integrals* - A hole of a radius of 1cm is pierced in a sphere...