A cylinder has a base diameter of 5 cm and a height of 8 cm.
The base diameter is increased by 15% and the height is decreased by 30%.
Find the percentage change in the volume of the cylinder.
Type each step of your working on a separate line.

Respuesta :

Answer:

The new volume is 81.2% of the prior, this is true for any for any values of radius and height, as long as they are changed as stated.

Step-by-step explanation:

The volume of a cylinder is given by:

[tex]V = \pi*r^2*h[/tex]

If we increase the diameter by 15%, then the radius is increased by 7.5% and the new radius is:

[tex]r_{new} = 1.075*r[/tex]

If we decrease the height by 30%, then the new height is 70% of the prior and is given by:

[tex]h_{new} = 0.7*h[/tex]

Applying to the volume formula we have:

[tex]V_{new} = pi*(r_{new})^2*h_{new}[/tex]

[tex]V_{new} = \pi*(1.075*r)^2*0.7*h\\V_{new} = 1.16*0.7*\pi*r^2*h\\V_{new} = 0.812*\pi*r^2*h\\V_{new} = 0.812*V[/tex]

The new volume is 81.2% of the prior, this is true for any for any values of radius and height, as long as they are changed as stated.