Speed has both … * 1 point a. magnitude and time. b. momentum and distance. c. direction and time. d. acceleration and direction.
The correct answer and explanation is:
Correct Answer:
a. magnitude and time.
Explanation (300 words):
Speed is a scalar quantity, which means it only has magnitude and no direction. In physics, speed refers to how fast an object is moving regardless of the direction in which it moves. It tells us the rate at which an object covers distance over a certain period of time.
The formula for speed is: Speed=DistanceTime\text{Speed} = \frac{\text{Distance}}{\text{Time}}
From this formula, you can see that speed depends on two things: the distance traveled and the time it takes. Therefore, speed has magnitude (how much) and is measured with respect to time, but it does not include direction. This is what distinguishes speed from velocity.
Velocity, unlike speed, is a vector quantity. It includes both magnitude and direction. For example, 60 km/h north is a velocity because it specifies both how fast and in what direction. In contrast, simply saying 60 km/h refers to speed.
Let’s break down the other options:
- b. momentum and distance – Momentum is a separate concept that includes mass and velocity, not directly related to speed alone.
- c. direction and time – This describes velocity, not speed.
- d. acceleration and direction – Acceleration is the rate of change of velocity, and it’s not a part of the definition of speed.
In conclusion, the correct understanding of speed is essential in motion-related physics. It helps to measure how fast something is moving, which is useful in transportation, athletics, engineering, and many other fields. Since it doesn’t involve direction, speed has magnitude and is measured over time—making option a the correct answer.