Calculate acceleration three ways: enter initial velocity and final velocity with a time interval (Δv/Δt method), provide distance and velocities, or use net force and mass (Newton's Second Law). Results are shown in m/s², ft/s², and g-force — choose whichever method matches your problem.
Acceleration (m/s²)
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Acceleration (ft/s²)
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Acceleration (g-force)
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Change in Velocity (Δv)
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Acceleration is the rate at which an object's velocity changes over time. It is a vector quantity, meaning it has both magnitude and direction. An object accelerates when it speeds up, slows down, or changes direction. The SI unit of acceleration is meters per second squared (m/s²).
The three main acceleration formulas are: (1) a = Δv / Δt — acceleration equals change in velocity divided by time; (2) a = F / m — from Newton's Second Law, acceleration equals net force divided by mass; and (3) a = (v₂² − v₁²) / (2d) — derived from kinematics using velocities and distance when time is unknown.
Using Newton's Second Law, acceleration (a) equals net force (F) divided by mass (m): a = F / m. For example, if a 70 kg object experiences a net force of 500 N, its acceleration is 500 / 70 ≈ 7.14 m/s². Make sure force is in Newtons and mass in kilograms to get m/s².
Yes. Negative acceleration means the object is decelerating — slowing down in the chosen positive direction. It can also indicate motion in the opposite direction. The sign depends on the coordinate system you define; if you define rightward as positive, leftward acceleration is negative.
Yes, acceleration is a vector quantity because it has both magnitude and direction. This distinguishes it from speed (a scalar). When an object changes direction — even at constant speed — it is still accelerating, as seen in circular motion.
If you know the net force and mass, use a = F / m. If you know initial velocity, distance, and time, use the kinematic equation a = 2(d − v₁·t) / t². These approaches let you solve for acceleration when the final velocity is not directly measured.
The standard SI unit is meters per second squared (m/s²). Other common units include feet per second squared (ft/s²) and g-force (g), where 1 g ≈ 9.80665 m/s². In the imperial system, poundal per pound (pdl/lb) is occasionally used in physics problems.
Velocity is the rate of change of position — how fast and in which direction an object moves. Acceleration is the rate of change of velocity — how quickly the velocity itself is increasing or decreasing. A car moving at a steady 60 mph has zero acceleration; a car speeding up has positive acceleration.