1. Air is leaking out from a sherical balloon.Find the % decrease in its volume when its surface area has decreased by 36%.
2.It is known that nearly 70% of the surface of the Earth are oceans.
The radius of the Earth is 6400km.Find the total area of the oceans on the Earth.
PLZ show the steps.
- myisland8132Lv 71 十年前最愛解答
let the radius of the original balloon is r1﹐the radius of the new balloon is r2
surface area has decreased by 36%
the volume of new balloon /the volume of original balloon
so the % decrease of volume of new balloon
the radius of the Earth is 6400km
the surface area of the Earth
the total area of the oceans on the Earth.