Is there more wood in a 70​-foot-high tree trunk with a radius of 2.1 feet or in a 60​-foot-high tree trunk with a radius of 2.4 ​feet? Assume that the trees can be regarded as right circular cylinders.


There is
nothing

ft
ft cubed
ft squared
of wood in the 70​-foot-high tree and
nothing

ft cubed
ft squared
ft
of wood in the 60​-foot-high tree. There is more wood in the

60
70
​-foot-high tree

Respuesta :

Answer:

There is more wood in a 60​-foot-high tree trunk with a radius of 2.4 ​feet

Step-by-step explanation:

* Lets talk about the right circular cylinder

- It has two circular bases

- The volume of it = Area of the base × its height

- The area of the base = πr²

- The quantity of wood in the tree is the volume of the cylinder

* Lets calculate the volumes the two trees and compare

 between them

- Volume of the first tree:

∵ Its radius = 2.1 feet

∴ The area of its base = π(2.1)² = 4.41π feet²

∵ Its height = 70 feet

∴ Its volume = 4.41π × 70 = 308.7π = 969.8 feet³

- Volume of the second tree:

∵ Its radius = 2.4 feet

∴ The area of its base = π(2.4)² = 5.76π feet²

∵ Its height = 60 feet

∴ Its volume = 5.76π × 60 = 345.6π = 1085.7 feet³

∵ 1085.7 > 969.8

∴ The volume of wood in 2nd tree > the volume of wood in 1st tree

* There is more wood in a 60​-foot-high tree trunk with a radius of 2.4 ​feet