Final answer:
A car with an acceleration of 10 m/s² is increasing its velocity by 10 m/s every second. The SI unit for acceleration is meters per second squared (m/s²). Positive acceleration indicates increasing velocity, whereas negative acceleration indicates decreasing velocity.
Step-by-step explanation:
Understanding Car Acceleration
If a car has an acceleration of 10 m/s², this means that every second, the car's velocity increases by 10 meters per second. This is a significant acceleration, indicating that the car is speeding up quite rapidly.
Units of Acceleration
Another unit of acceleration is the gravitational acceleration (g), which is approximately 9.8 m/s² on Earth's surface. However, the standard unit for acceleration in the International System of Units (SI) is m/s², also known as meters per second squared.
Positive vs Negative Acceleration
Positive acceleration means the velocity of an object is increasing, while negative acceleration, often referred to as deceleration, means the velocity is decreasing. It's important to remember that acceleration is a vector, which means it has both magnitude and direction. Therefore, whether an acceleration is positive or negative depends on the direction of the velocity change relative to the initial motion.