What is acceleration?

• A. Going only as fast as the acting body makes it
• B. The rate of velocity change
• C. The measure of total force
• D. The resistance to motion

Answer: (A)

Acceleration is the rate at which velocity changes over time. Velocity combines speed and direction, so any change in how fast you’re going or which way you’re moving is acceleration. If you speed up, you’re accelerating in the forward sense; if you slow down, your velocity is decreasing, which is also acceleration, just in the opposite sense. Even if your speed stays the same but you alter direction—like turning a corner—you experience acceleration because your velocity vector is changing. The standard units are meters per second squared (m/s^2), and the change in velocity over the time it takes for that change (Δv/Δt) defines the magnitude and direction of the acceleration. This includes cases like a patrol car speeding up, braking to stop, or navigating a curve where the direction changes, all of which involve acceleration.