A Policeman in a Stationary Car Measures the Speed of Approaching

question 52

Multiple Choice

A policeman in a stationary car measures the speed of approaching cars by means of an ultrasonic device that emits a sound with a frequency of 41.2 kHz. A car is approaching him at a speed of 33.0 m/s. The wave is reflected by the car and interferes with the emitted sound producing beats. What is the frequency of the beats? The speed of sound in air is 330 m/s.

• A) 9.2 kHz
• B) 4.1 kHz
• C) 4.6 kHz
• D) 1.2 kHz
• E) 8.2 kHz

Understand the principles guiding the design and operation of accounting information systems.

Understand how to use wildcards for pattern matching in queries.

Know how to combine criteria using AND in query design.

Comprehend the principles of sorting records in a database.

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Definitions:

Relational Operators

Symbols that are used to compare two values and determine the relationship between them.

Pointers

Variables in programming that store memory addresses of other variables, allowing for indirect manipulation of those variables.

Variables

Elements of programming that are used to store data, such as numbers, texts, or arrays, which can then be manipulated by the program.

Data Type

Categorizes the different types of data that can be processed by a computer, such as integers, floating-point numbers, and characters.