## What is Acceleration?

Teachers, use this lesson plan with the acceleration study guide, to explain the concept of acceleration as it applies to motion in science. This lesson plan introduces acceleration to Physical Science students in an easy to understand, simplified format. Review the following information with your students to introduce them to the notion of acceleration.

Have you ever been in a car that turns a corner and the force presses you against the door or the car seems to change speed?

In science, there is a formula for virtually every aspect of motion. This feeling that you have in the car is no different. The change is called acceleration and there is a formula to figure out the exact acceleration of the car. So, what exactly is acceleration? Acceleration is the result of a change in velocity. Since speed is part of velocity, acceleration can be accomplished through changing speed, velocity or both.

The general public views acceleration as an increase in speed, but this is not strictly true. Acceleration can be the result of the increase of speed, but a decrease in speed can also cause acceleration in the form of deceleration. A change in velocity changes the acceleration. Therefore, any change in speed *or direction *can cause acceleration since both are components of velocity.

## Velocity Board Work

Teachers, place the following questions on the board to be discussed by the class or ask the following questions out loud to assess student understanding of acceleration. After discussing the following information with the class, review the formula for average acceleration with students.

- If a child is running across the playground and suddenly turns without changing speed, does this cause a change in acceleration, and if so why?
- A truck is driving in a straight line at a speed of 75 mph. They pass a police car on the side of the road and slow down to avoid being pulled over. Is this a form of a change of acceleration? If so, what is it called?
- Acceleration is determined by a change in velocity. Consider what type of quantity velocity is and answer the question — is acceleration a vector or scalar quantity?

Please be sure that students understand what causes acceleration and what quantities must be known to determine acceleration, then ask students to review the acceleration study guide to reinforce their knowledge on the subject of acceleration.