How to Calculate Acceleration Rate

Acceleration can measure how fast a car speeds up.

Acceleration measures how quickly an object is increasing or decreasing its velocity, such as a car building up speed after a red light turns green or a skier going faster down a hill. Acceleration is measured in units of distance per second squared, such as feet per second squared or yards per second squared. In order to calculate the average acceleration rate, you need to know the initial velocity, the final velocity and the elapsed time.

Things You'll Need

• Calculator
• Stopwatch/Timer

Instructions

1. Determine the speed of the object at the start and at the end of the observation period. For example, you could use the speedometer on a car to find that it was going 0 feet per second when the car was stopped and was going 44 feet per second (30 miles per hour) when it stopped accelerating.

2. Measure the time it took to accelerate with a stopwatch or timer. For example, it may have taken the car four seconds to accelerate from a stop to 44 feet per second.

3. Calculate the change in velocity by subtracting the initial speed from the final velocity. In this example, you would subtract 0 feet per second from 44 feet per second to find the change in velocity to be 44 feet per second.

4. Divide the change in velocity by the time elapsed to calculate that average acceleration. In this example, you would divide 44 feet per second by 4 seconds to find the average acceleration to be 11 feet per second squared.

References

• Batesville High School: Acceleration
• Physics Classroom: Acceleration