A composite solid consists of a cone with height 4 cm on top of a hemisphere with radius 5 cm. If the outside surface of the composite solid is to be painted at a cost of $0.05 per , calculate the total cost of painting the solid. Use and round your answer to the nearest cent.
[6]A composite solid is formed by joining the base of a hemisphere of radius to the base of a cone with radius and height .
A second composite solid is formed by joining a hemisphere and a cone, where both the radius and the height of the cone are doubled compared to the original solid (so that for the new solid and ).
Determine the ratio of the total surface area of the new solid to that of the original solid. Express your answer in simplest form.
[5]A hollow shell is created by removing a smaller hemisphere of radius and a smaller right circular cone of radius and height from the inside of the original composite solid (hemisphere + cone) with and . Calculate the volume of the remaining material. Give your answer in terms of .
[6]