Question

A 12 cm by 12 cm ice cube tray is in the shape of a cuboid with twelve hemispheres inset. The depth of each hemispheres is 1 cm.
a) If all the hemispheres were filled with water, calculate the total volume of water that the ice cube tray could hold.

It is now desired to paint the top of the ice cube tray a pleasant shade of blue.
b) calculate the rusface area of one hemisphere on the tray.
c) Calculate the total surface area of the top of the ice cube tray.

Thank you so much for huge help!!!!!

Answer 1

if the depth of each hemisphere is 1, the that is also the radius.

a) you know how to find the volume of half a sphere, right?

b) same for surface area

c) the flat area of the top of the tray is 12x12 minus the area of 12 circles with radius 1. Now add on 12 hemispheres for the total surface area.

Answer 2

Thank you so much, a) 25.1 cm^3
b) 6.28 cm ^2
c)144-75.36 =68.64
Is it correct?
Thank you so much