Learn to Program using Alice

Practice Test for the Lesson Titled

Objects in 3D Space

Published April 23, 2007
By Richard G. Baldwin

File: Alice0110PracticeTest.htm


Questions

1.  Which item does not belong in the following list?  Every Alice object has a viewpoint.  The viewpoint of an object is determined by:

Answer and Explanation

2.  True or False:  Every Alice object has a center point and three axes.

Answer and Explanation

3.  True or False:  The center point is the position in space (relative to the object) at which that object's three coordinate axes cross.

Answer and Explanation

4.  True or False:  The center point of an object is always physically inside the object.

Answer and Explanation

5.  True or False:  If you move an Alice object, you are actually moving its center point.  The rest of the object comes along for the ride.

Answer and Explanation

6.  True or False:  It is not possible to break the connection between an object and its component parts.  For example, you could not cause a Coach object to move away and leave his arms behind.

Answer and Explanation

7.  True or False:  If you turn an Alice object to the right or to the left, you are rotating the object around its blue axis.

Answer and Explanation

8.  True or False:  If you turn an Alice object forward or backward, you are rotating the object around its red axis.

Answer and Explanation

9.  If you roll an Alice object to the right or the left, you are rotating the object around which axis?

Answer and Explanation

10.  True or False:  When you rotate an object around one of its axes, that axis remains stationary and the other two axes do the rotation.

Answer and Explanation

11.  True or False:  The terms move, turn, and roll are simply jargon that are used to describe certain kinds of motion in Alice.

Answer and Explanation

12.  True or False:  A 3D coordinate system is typically thought of as consisting of three axes where the angle between any pair of axes is forty-five (45) degrees.

Answer and Explanation

13.  True or False:  In mathematical terminology, the axes in a 3D coordinate system are orthogonal.

Answer and Explanation

14.  True or False:  Scientists and engineers typically think of the three axes in a 3D coordinate system as the horizontal axis (often called X), the vertical axis (often called Y), and a third axis that is perpendicular to the plane formed by X and Y (often called Z).

Answer and Explanation

15.  True or False:  Alice doesn't deal with X, Y, and Z axes.  Rather, Alice deals with one axis that runs from left to right, a second axis that runs from bottom to top, and a third axis that runs from front to back.

Answer and Explanation

16.  In Alice, what is the color of the axis that protrudes out in front of an object?

Answer and Explanation

17.  In Alice, what is the color of the axis that protrudes out to the right of an object?

Answer and Explanation

18.  In Alice, what is the color of the axis that protrudes out from the top of an object?

Answer and Explanation

19True or False:  When discussing the colors of the coordinate axes in Alice, the directions front/back, right/left, and up/down are relative to the viewpoint of the object, and not relative to the viewpoint of you the viewer.

Answer and Explanation

20True or False:  Every object in the gallery has a center point, which is the origin where the three axes join with respect to that object's viewpoint.

Answer and Explanation

21True or False:  The center point for a penguin is at a point in space on the ground midway between the penguin's feet.

Answer and Explanation

22True or False:  Many gallery objects are made up of component parts.

Answer and Explanation

23.  Which item does not belong in the following list?  A penguin object is made up of the following smaller component objects:

Answer and Explanation

24True or False:  Each component object belonging to an object may itself be composed of even small component objects.

Answer and Explanation

25True or False:  The component objects that make up a larger object do not have their own center points and axes.

Answer and Explanation

26True or False:  In order to cause a penguin to flap a wing, we must know the position of the wing object's center point, but we do not need to know the directions of the red, green, and blue axes that go through the center point for that wing.

Answer and Explanation

27True or False:  Given the Alice convention for color-coding the three axes, we would normally expect the red axis to protrude from the top of the cockpit for an airplane object.

Answer and Explanation

28.  Which item does not belong in the following list?

Answer and Explanation

29True or False:  The combination of all possible rotational motions and all possible translational motions results in what is often called eight degrees of freedom.

Answer and Explanation

30True or False:  Because the ground represents terra firma in an Alice world, it cannot be turned or rotated.

Answer and Explanation

31True or False:  When an object's opacity is set to 100%, it is totally transparent.

Answer and Explanation

32True or False:  Every object has a center point and has its own set of 3D axes. The center point and the 3D axes belonging to an object travel with and rotate with the object, independently of the other objects in the world.

Answer and Explanation

33True or False:  If you add a Coach object to your world and immediately turn his left arm to the LEFT by 90 degrees, that will place the arm in a position that most people would consider to be comfortable.

Answer and Explanation

34True or False:  If you add a Coach object to your world and immediately roll his left arm to the RIGHT by 80 degrees, that will place the arm in a position that most people would consider to be comfortable.

Answer and Explanation

35True or False:  If you add a Coach object to your world and immediately roll his left arm to the LEFT by 45 degrees, that will place the arm in a position that most people would consider to be comfortable.

Answer and Explanation

36True or False:  If you add a Coach object to your world and immediately turn his left arm BACKWARD by 140 degrees, that will place the arm in a position that most people would consider to be comfortable.

Answer and Explanation

37True or False:  If you add a Coach object to your world and immediately turn his left arm to the RIGHT by 90 degrees, that will place the arm in a position that most people would consider to be comfortable.

Answer and Explanation

38True or False:  The center point for a Coach object's left arm is approximately half way between his left shoulder and his left wrist.

Answer and Explanation



Copyright 2007, Richard G. Baldwin.  Faculty and staff of public and private non-profit educational institutions are granted a license to reproduce and to use this material for purposes consistent with the teaching process.  This license does not extend to commercial ventures.  Otherwise, reproduction in whole or in part in any form or medium without express written permission from Richard Baldwin is prohibited.


The following image is the splash screen from Alice 2.0, and is the property of the developers of Alice at Carnegie Mellon.

Answers and Explanations


Answer 38

False.

Explanation 38

Back to Question 38
 


Answer 37

True.

Explanation 37

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Answer 36

True.

Explanation 36

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Answer 35

True.

Explanation 35

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Answer 34

True.

Explanation 34

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Answer 33

False.

Explanation 33

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Answer 32

True.

Explanation 32

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Answer 31

False.

Explanation 31

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Answer 30

False.

Explanation 30

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Answer 29

False.

Explanation 29

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Answer 28

B.  turn

Explanation 28

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Answer 27

False.

Explanation 27

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Answer 26

False.

Explanation 26

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Answer 25

False.

Explanation 25

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Answer 24

True.

Explanation 24

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Answer 23

C.  right hand

Explanation 23

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Answer 22

True.

Explanation 22

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Answer 21

True.

Explanation 21

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Answer 20

True.

Explanation 20

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Answer 19

True.

Explanation 19

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Answer 18

B.  green

Explanation 18

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Answer 17

A.  red

Explanation 17

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Answer 16

C.  blue

Explanation 16

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Answer 15

True.

Explanation 15

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Answer 14

True.

Explanation 14

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Answer 13

True.

Explanation 13

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Answer 12

False.

Explanation 12

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Answer 11

False.

Explanation 11

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Answer 10

True.

Explanation 10

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Answer 9

C.  blue

Explanation 9

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Answer 8

True.

Explanation 8

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Answer 7

False.

Explanation 7

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Answer 6

False.

Explanation 6

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Answer 5

True.

Explanation 5

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Answer 4

False.

Explanation 4

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Answer 3

True.

Explanation 3

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Answer 2

True.

Explanation 2


Back to Question 2


Answer 1

B.  The width of the object.

Explanation 1

Back to Question 1


Copyright 2007, Richard G. Baldwin.  Faculty and staff of public and private non-profit educational institutions are granted a license to reproduce and to use this material for purposes consistent with the teaching process.  This license does not extend to commercial ventures.  Otherwise, reproduction in whole or in part in any form or medium without express written permission from Richard Baldwin is prohibited.

The following image is the splash screen from Alice 2.0, and is the property of the developers of Alice at Carnegie Mellon.

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