# Investigating Speed and Acceleration Using Tornado Tubes

#### Summary

In this activity, students will use a plywood ramp and various tornado tubes (made from tornado tube connectors and 2 liter pop bottles) to calculate the average speed of the tornado tubes. They will set up 4 investigations filling the 2 liter pop bottles with different amounts of water to see if mass affects the speed and acceleration of the tornado tube as it travels down the plywood ramp. The students will journal the outcome of each investigation and compare their data to see if mass does affect speed and/or acceleration.

## Learning Goals

In this activity the students will learn to calculate speed and acceleration. They will learn the definition of speed, velocity, and acceleration. Through their calculations and their drawings, they will observe and analyze what affect mass has on the speed of an object.

## Context for Use

This is a classroom activity that can be done with a large group of students. The tornado tubes and the large ramp make it easy for students to observe. Due to the need to repeat the investigation many times, all the students can get involved in the time keeping on a rotating basis. This investigation will take 3-4 45 minute class periods depending how much time you need to allow for journaling and time to calculate results.

## Description and Teaching Materials

**Materials:**

10- 2 liter pop bottles

5- Plastic tornado tube connectors

3 x 8 ft. piece of plywood

Stop watch

Student Journals

Using the tornado tube connectors, connect the 2 liter bottles so that you have 5 assembled tornado tubes. Leave one pair empty, fill one pair ¼ full of colored water, one pair ½ full, one pair ¾ full, and the last pair entirely full.

On a rotation basis, allow students time to roll the various tornado tubes down the ramp. Also, allow the students time to experiment with the height of the ramp. Explain that they will be using the ramp and the tubes to help define and calculate speed, velocity, and acceleration. Have students define each of these words in their science journals.

To begin the investigation, students will release the tornado tubes at the top edge of the ramp. Using a stopwatch, they will check to see how many seconds it takes for the tornado tube to reach the end of the ramp. Distance divided by time = avg. speed. Students will test each tornado tube 3x to find an average. Students will create a table to compare the results from the various tubes to answer the question, "Does the amount of mass affect speed?"

Velocity is the speed of an object in a particular direction. In this case, velocity would be the speed of the tornado tube down the ramp or the speed of the tornado tube traveling east/west etc. Since acceleration is the rate at which velocity changes, students can then use a stopwatch to see if acceleration at the top half of the ramp equals the acceleration at the bottom half of the ramp. To calculate acceleration, students need to time how long it takes for the tube to get from one point to the next on the ramp. For example: One student will use a stopwatch to find out how much time it takes to get from the top of the ramp to the midpoint and another student will record the time it takes to get from the middle to the end of the ramp. By finding the difference, students can determine if there is positive or negative acceleration when comparing the top and bottom portion of the ramp.

## Teaching Notes and Tips

Be sure to instruct student to simply RELEASE the tube down the ramp rather than propel the tube down the ramp. Also, note that acceleration can change if the direction of the tube changes. It is important for students to know that a change in acceleration of an object is a change in speed, direction, or both. If the tornado tube has more water in one bottle than the other, this can cause a change in direction.

## Assessment

Students will be assessed for understanding through information found in their journals and classroom discussion.

## Standards

This activity aligns with Minnesota Standard in Physical Science Strand II - Sub-Strand D. Motion. The standard states that students will describe the motion of objects. Benchmark #1. The student will use a frame of reference to describe the position, speed, and acceleration of an object.