The movement of a car can help students visualize acceleration.
Acceleration is the change of speed over time. For many students, acceleration is a hard concept to grasp. Fortunately for the physical science teacher, many activities can help students visualize how acceleration affects objects. From using motion detectors to graphing an object's motion, these activities provide opportunities for students to comprehend the importance of acceleration.
Acceleration and Motion Detector Activities
You can design many activities around motion and acceleration detectors. Allow students to construct apparatuses that allow an object to move while simultaneously being measured, such as an inclined plane with a cart. Using the motion and acceleration detectors together, students can find the change of speed of the moving object. This change in speed is by definition that object's acceleration. One specific activity using a motion detector is to roll a cart along an inclined surface. By mounting the acceleration detector on the cart and mounting the motion detector at the top of the surface, you can monitor the acceleration of the cart as it moves.
Objects of Different Sizes
Activities examining the acceleration of objects of different sizes will teach students that gravity applies the same constant acceleration to all objects. Give students multiple objects of different sizes but with similar air resistance. In addition, give the students stopwatches. Tell the students to measure the time it takes for each object to fall from a given distance. They should soon discover that they all fall in the same amount of time. Ask them to interpret this result.
Graphs of Moving Objects
Because acceleration describes the relationship of speed versus time, you can display for students a moving object with varying speed during a fixed time period. Allow the students to watch the moving object while estimating the change in acceleration. For example, you can move a toy along a toy roller coaster track. After setting up the roller coaster track, draw axes for speed versus time on the board. Instruct one student to move the toy along the roller coaster track, while another student draws the corresponding curve on the axes you drew. Remind students that when the toy is accelerating, the slope of the curve will be positive; when the toy is not accelerating, the curve will reach a maximum or minimum; and when the toy is decelerating, the slope of the curve will be negative.
Galileo Experiments
In this activity, students will erect a ramp that allows objects to slide down. Give students a toy car, a block, a board and a stopwatch. Instruct the students to design a ramp with the objects so that they can measure the time it takes the car to descend from the top of the ramp. The students should use the stopwatch to time the car's decent and use that time to calculate the average acceleration of the car using the formula [(final speed - initial speed) / time].
Tags: change speed, coaster track, curve will, moving object, roller coaster
