The distance traveled by an object per unit time is called a. velocity b. speed c. momentum d. acceleration
The correct answer and explanation is:
Correct Answer: b. speed
Explanation (300 words):
Speed is a fundamental concept in physics and everyday life. It refers to the distance traveled by an object per unit of time. In other words, speed tells us how fast an object is moving regardless of the direction it is going. The standard unit for speed in the International System (SI) is meters per second (m/s), but it can also be expressed in kilometers per hour (km/h) or miles per hour (mph) depending on the context.
The formula for speed is: Speed=DistanceTime\text{Speed} = \frac{\text{Distance}}{\text{Time}}
For example, if a car travels 100 kilometers in 2 hours, its speed is: 100 km2 h=50 km/h\frac{100 \text{ km}}{2 \text{ h}} = 50 \text{ km/h}
It is important to distinguish speed from velocity. While speed is a scalar quantity (it has only magnitude), velocity is a vector quantity, which means it includes both magnitude and direction. If you say a car is moving at 60 km/h to the north, you’re describing its velocity. If you just say 60 km/h, you’re describing its speed.
The other options in the question are different physical concepts:
- Velocity (a) includes direction, as mentioned.
- Momentum (c) is the product of an object’s mass and velocity and represents the quantity of motion the object has.
- Acceleration (d) is the rate of change of velocity over time—how quickly an object speeds up or slows down.
In summary, the correct term for the distance an object travels per unit of time, without regard to direction, is speed. It provides a simple yet essential way to describe motion in physics, engineering, and daily experiences.