Which is a valid velocity reading for an object?
A. 45 m/s
B. 45 m/s north
C. 0 m/s south
D. 0 m/s
Answer (2)
Velocity is a vector with magnitude and direction.
45 m/s north includes both magnitude and direction.
0 m/s south and 0 m/s are valid as zero velocity.
The most complete valid velocity reading is: 45 m/s north
Explanation
Understanding Velocity To determine which option is a valid velocity reading, we need to remember that velocity is a vector quantity. This means it has both magnitude (speed) and direction. A valid velocity must specify both, or be zero. Let's examine each option:
Analyzing the Options
45 m/s: This only provides the magnitude (speed) but no direction. Therefore, it's not a complete velocity reading.
45 m/s north: This gives both magnitude (45 m/s) and direction (north). This is a valid velocity.
0 m/s south: This gives a magnitude of 0 and a direction (south). Since the magnitude is zero, the direction is irrelevant, and this is a valid velocity. Zero velocity means the object is not moving, so direction doesn't matter.
0 m/s: This gives a magnitude of 0 and no direction. This is also a valid velocity for the same reason as above.
Determining Valid Readings From the analysis, we can see that '45 m/s north', '0 m/s south', and '0 m/s' are all valid velocity readings because they either specify both magnitude and direction or have a magnitude of zero.
Selecting the Best Answer The question asks for which is a valid velocity reading, implying a single correct answer. Among the options, '45 m/s north' is the most complete and conventional way to express velocity when it is non-zero. While '0 m/s south' and '0 m/s' are technically correct, '45 m/s north' is the best answer in this context.
Examples
Understanding velocity is crucial in many real-world scenarios. For example, when planning a flight, pilots need to consider the plane's velocity relative to the wind to ensure they reach their destination on time. Similarly, athletes use velocity to optimize their performance, such as a sprinter adjusting their speed and direction to achieve the fastest time. In everyday life, knowing the velocity of a car helps drivers maintain safe distances and avoid collisions. These examples highlight how a clear understanding of both speed and direction is essential for making informed decisions and achieving desired outcomes.
The valid velocity readings are '45 m/s north', '0 m/s south', and '0 m/s', but the most complete answer is '45 m/s north'. This reading specifies both magnitude and direction, making it the best choice among the options. The question asks for a single valid reading, thus '45 m/s north' is the appropriate answer.
;
