Note: I'm assuming that your teacher wants you to use the approximation pi = 3.14 ------------------------------------------------------- Problem 1)
Plug the value r = 4.5 into the formula below to find the approximate volume
V = (4/3)*pi*r^3 V = (4/3)*pi*(4.5)^3 V = (4/3)*pi*91.125 V = (4/3)*91.125*pi V = 121.5*pi V = 121.5*(3.14) V = 381.51
So the approximate volume of this sphere is roughly 381.51 cubic cm
Note: we can write "cubic cm" as "cm^3" ------------------------------------------------------- Problem 2)
The formula to use for the volume of a cylinder is V = pi*r^2*h where r is the radius and h is the height
In this case, we have r = 2.1 and h = 8.0
V = pi*r^2*h V = pi*(2.1)^2*8.0 V = pi*4.41*8.0 V = pi*35.28 V = 35.28*pi V = 35.28*(3.14) V = 110.7792
The volume is roughly 110.7792 cubic cm ------------------------------------------------------- Problem 3)
Now we use the formula V = (1/3)*pi*r^2*h which is the volume of a cone. Note how this is simply 1/3 the volume of the cylinder (with same radius and height)
Use r = 8.0 and h = 2.0
V = (1/3)*pi*r^2*h V = (1/3)*pi*(8.0)^2*(2.0) V = (1/3)*pi*64*2 V = (1/3)*pi*128 V = (1/3)*128*pi V = (128/3)*pi V = (128/3)*(3.14) V = 133.973333
