Volume Formulas: Cones, Cylinders, and Spheres

Transcription

1 Volume Formulas: Cones, Cylinders, and Spheres Purpose: This tutorial will aid students in the memorization of the formulas for the volume of cones, cylinders, and spheres. Included Alice topics: Adding Objects, Changing an object's color, Object methods, Copying Object methods, Looping

2 Introduction to Alice Open the program by clicking on the Alice icon. After the program loads choose the grass template in the opening window. Next, choose File from the drop down menu, then Save World Save the World as: Volume.yourname

3 A WORD OF CAUTION Sometimes we make a mistake as we work in Alice. Fixing a mistake is much easier than you think, as long as you do it quickly. As soon as you make a mistake, simply click the Undo button! You can click it as many times as you need. So if you move the ground by mistake or any number of other error, remember: UNDO IS YOUR FRIEND!

4 Begin by adding a Cone, Cylinder and Sphere to your world First click the green Add Objects button Scroll over to the Shapes folder and click to find all the available shapes in Alice After clicking on the Class Cone, click Add instance to world Continue the same process for the Class Cylinder and Class SphereHighPoly They will all probably dump on top of each other. That's fine, we'll fix it in a minute.

5 Removing the grass from your World In the upper left corner of Alice is the Object Tree Box, click on ground. Below that box is the Details Area. There are 3 tabs in this box. Click on the Properties tab. Find Is Showing. Change it from true to false by pulling down the white arrow to the right of true. Your world will now be totally blue except for the white shapes in a pile at the middle of your screen.

6 Moving the Shapes Let's look at the World section (where the shapes you dropped into your World are located) Now they're all piled on top of each other. Let's separate them. To move them use the buttons located to their right. Explore the first six buttons to discover their functions as you place your shapes. Note: DO NOT USE THE 7 th BUTTON. (It adds copies to your world and we only need our three shapes.)

7 Changing the Shapes Color Right click on the Sphere. From the drop down menu choose: Methods, then spherehighpoly set color to: Yellow Use the same procedure to change the Cylinder to Purple and the Cone to Green

8 Animation Click the green Done button. Click on the now yellow sphere in the world section. Notice also that the spherehighpoly is highlighted in the Object Tree window. Now we will be allowed to animate the sphere. Click on the method's tab in the Detail window. We'll make the Sphere bob up and down to call attention to itself.

9 Animation-Moving the Sphere Up Use your arrow, left click on the gray section to the left of the words spherehighpoly move. Drag this command on top of the Do Nothing under the World.my first method tab in the Editor Area. Choose Up, then 1 meter from the drop down menus.

10 Animation-Making the Sphere Bob Right click on right of the move command and choose make copy. Now change the Up to Down using the arrow to the right of Up in the second move command. The sphere really won't bob now, so we need to add a Loop. From the bottom of the Editor area, drag up the Loop command above the first move command. (You'll see a green line showing you the final placement of the command.)

11 Animation-Making the Sphere Bob continued: Choose 2 times from the menu Now drag the two move commands into the loop command. Test to see if the sphere bobs up and down by pressing the Play button located in the upper left. (The animation will play in a separate window.) x out of the pop up animation window.

12 Animation-The Sphere Speaks Drag in the method spherehighpoly think. Choose I wonder from the drop down menu. Drag in the method spherehighpoly say. Choose other from the drop down menu. In the pop up, enter the string: How can I find my Volume?

13 Animation-The Cylinder Answers Use the same technique as with the Sphere to have the Cylinder bob up and down before answering the Sphere. Drag into world.my first method a Cylinder say I know, I know! Drag in a Cylinder say The volume formula for a sphere is 4/3 times pi times radius cubed. Next, drag in a Cylinder think But what's the formula for my volume?

14 Finishing the Animation Using the methods learned from the Sphere, animate the shapes to inform each other of their volume formulas. (All the formulas are listed on the next page.) Hint: Timing. Change the duration for each of the says and thinks to make the animation easier to read. To do this pull down the arrow after more, then duration and finally choose two seconds. (You may also choose other and then use the pop up calculator in input your own numerical choice.)

15 Volume Formulas Sphere: 4/3 times pi times radius cubed Cylinder: pi times radius squared times height Cone: 1/3 times pi times radius squared times height