AP CSP Unit 1

Which of the following best describe examples of abstraction?

Select two answers.

• A series of steps for creating a model airplane is laid out in a clear order, with specific instructions in great detail for completing each step.

• Several developers are working on a program together. In order to complete the work efficiently, they split the program up into several parts, and each work on a section, testing as they proceed. When code is complete they add it to a master program.

• A sheet of music for guitar is written as a series of chords (e.g C, Am, G7). Each of these represents multiple notes which are played simultaneously on different strings of a guitar.

• A developer writing a program for calculating properties of shapes uses a variable pi to store a decimal approximation of the number π (~3.14159). They use this variable whenever they need to use the number π to calculate an area or volume.

Rick is in charge of a team developing a program which will be used by businesses to control stock. The team has already consulted with potential clients and developed an idea of what inputs will be required and the likely outputs that will be produced from these inputs. Which of the following should Rick and his team do next?

• Write segments of code in different languages to see which language will be most suitable for the job.

• Plan the structure of the program and determine how the major algorithms will work.

• Make a list of bugs which will occur during development and propose ways these could be fixed.

• Decide on the schedule for updates and maintenance of the code.

Which of the following is a simplified but equivalent Boolean expression to the following:

(X > 0 AND X ≤ 20) OR (X > -5 AND X < 15)`

• (X < -5) AND (X ≥ 20)

• (X > 0) AND (X < 15)

• (X < 0) AND (X > 15)

• (X > -5) AND (X ≤ 20)

Consider constructing an algorithm for a robot that can only perform the following three predefined operations.

MOVE_FORWARD ( ): The robot moves one square forward in the direction it is facing.

ROTATE_LEFT ( ): The robot rotates in place 90 degrees counterclockwise (i.e., makes an in-place left turn).

ROTATE_RIGHT ( ): The robot rotates in place 90 degrees clockwise (i.e., makes an in-place right turn).

Which of the following algorithms could successfully cause the robot to trace out a “T”-shaped path as drawn above?

• Step 1: MOVE_FORWARD ( )

  Step 2: ROTATE_LEFT ( )

  Step 3: ROTATE_LEFT ( )

  Step 4: MOVE_FORWARD ( )

  Step 5: ROTATE_RIGHT ( )

  Step 6: MOVE_FORWARD ( )

• Step 1: MOVE_FORWARD ( )

  Step 2: MOVE_FORWARD ( )

  Step 3: ROTATE_LEFT ( )

  Step 4: MOVE_FORWARD ( )

  Step 5: MOVE_FORWARD ( )

  Step 6: ROTATE_RIGHT ( )

  Step 7: ROTATE_RIGHT ( )

  Step 8: MOVE_FORWARD ( )

• Step 1: MOVE_FORWARD ( )

  Step 2: MOVE_FORWARD ( )

  Step 3: ROTATE_RIGHT ( )

  Step 4: MOVE_FORWARD ( )

  Step 5: ROTATE_RIGHT ( )

  Step 6: ROTATE_RIGHT ( )

  Step 7: MOVE_FORWARD ( )

• Step 1: MOVE_FORWARD ( )

  Step 2: MOVE_FORWARD ( )

  Step 3: ROTATE_LEFT ( )

  Step 4: ROTATE_LEFT ( )

  Step 5: MOVE_FORWARD ( )

  Step 6: ROTATE_RIGHT ( )

  Step 7: MOVE_FORWARD ( )

  Step 8: MOVE_FORWARD ( )

Jama is creating a program which calculates the square roots of whole numbers. The program will store the results of each square-root as a variable. Which of the following data-types would be best used for this variable?

• int

• bool

• string

• float

Roxanne is writing a program which will be used to display information to passengers on a flight. Some of the variables she will use for her program are as follows.

speed - the current speed of the airplane relative to the ground in meters per second

passengers - the number of passengers on-board the plane

destination - the name of the destination airport of the flight

Which of the following correctly describes the types which would be best used for each of these variables?

• speed - string, passengers - int, destination - float

• speed - float, passengers - string, destination - int

• speed - float, passengers - int, destination - string

• speed - int, passengers - float, destination - string

Which of the following describes algorithmic solutions to problems:

I. A set of step by step instructions for assembling a piece of furniture.

II. A flowchart used to make important decisions on which actions to take in an emergency situation

III. A recipe for baking a cake with detailed numbered steps to follow

• I, II, and III

• I and III only

• II and III only

• I and II only

Which of the following is an example of code written in a high-level programming language?

• Add the number 2 to the number 5, then subtract this from the number 10 and display the answer.

• LD R0 8

  LD R1 3

  SUB R1 R0

  LD R2 1

  ADD R2 R0

  ST R0 X

• num1 = 8 - 3

  num2 = 2 * num1 + 1

  print(num2)

• 00101100

  01010000

  11011000

  10110111

Which of the following statements comparing low-level programming languages (such as assembly language) and high-level programming languages (such as python or java) are correct?

Select two answers.

• A program written in a low-level language is closer in syntax to the binary code understood by computers than a program written in a high-level language.

• A program written in a high-level language will usually be easier for a person reading the code to understand than one written in a low-level programming language.

• A low-level programming language is easier to learn, but some algorithms can only be written using high level programming languages.

• A low-level program can be easily understood and assembled on any hardware, while the use of a compiler means a high-level program is difficult to use on different systems.

Which of the following statements about variables in programming are true?

I. Variables allow a value to be stored for future use

II. Once the value of a variable is set it cannot be changed

III. The name given to a variable is important for human comprehension, but not for the computer.

• I, II, and III

• II only

• I and III only

• I only