Try it on paper first. A hint, the key idea and the worked solution are here when you need them.
A solid metal cone has radius and height . It is melted and made into a cylinder of radius . Find the height of the cylinder. If the same cone were made into solid balls of radius instead, how many balls would it make?
When a solid is melted and recast, its volume stays the same. If pieces are made, the old volume equals times the volume of one piece. The surface area does not stay the same. Change all lengths to one unit first.
Have you tried it?
Work it out on paper first. It is fine to get stuck or make a mistake: that is how we learn. When you are ready, go through the solution one step at a time, and check each step against your own.
Step 1. The cone. .
Step 2. The cylinder. , so .
Step 3. One ball. .
Step 4. The number. .
Answer: the cylinder is high, and the cone makes balls.
Log in to join the discussion.
Loading…