# Motion, Force, and Models

## Materials needed:

• Steel balls ( 3 sizes)
• Ramp
• Foam runways
• Meter tape
• Cork

## Vocabulary:

Collision: when one object hits another one, the objects collide

Stationary: an object that is not moving

Work: action of moving a mass

Friction: The resistance one object or surface encounters when moving over another

Energy: is transferred when work is done

Transfer of energy: when a moving object (ball) collides with a stationary object ( cork) energy transfers from the rolling balls to the cork

## Explanation of experiment

Independent variable: Size of the ball, Starting position of the ball

Dependent Variable: The distance of the cork

Constant: Cork

9 trails

6 different levels

## Pictures of the experiment

Picture #1: Represents the way your materials should look before starting your investigating.

Picture #2: Shows us testing the large ball at level 4.

Picture #3: Shows the ball and the cork colliding and you can see the transfer of energy happening.

## Conducts Investigation

Your students should be conducting the experiment and recording their measurements of how far the corked moved on their data tables.

In the picture below you can see that students are using 3 different ball sizes and 3 different starting positions.

They start with one ball size then experiment with the different starting positions. Then move onto the next ball size and experiment with those starting positions and repeat this process one more time so they have experimented with 3 different ball sizes (large, medium and small) and experimented at 3 different starting positions ( 2, 4, and 6)

## Overview of Content: How fast do balls travel?

After your students have finished the energy transfer worksheet, they will move on the the "How fast do balls travel?" Worksheet.

Within this worksheet we will be looking at different sized balls starting at the same starting positions and calculate what we found.

We will also be looking at the different starting positions for the same ball size and calculate those findings.

## Results: Graph from our Energy Transfer worksheet

The graph shows what the data collected in experiment looks like.

The blue line represents the large ball.

The green line represents the medium ball.

The yellow line represents the small ball.

## Analysis of Data

This investigation provides experiences with the crosscutting concepts of:

• Energy and Matter: Energy transfers as balls move and collide with other objects.
• Students can observe the transfer of energy from the steel ball to the cork as the cork moves down the foam ramp.

• Cause and Effect: The mass and speed of a rolling ball affect the amount of work it can do.
• Students will record their data on a chart which can then be analyzed in order to draw conclusions about how the mass of the ball affects its speed. Patterns can be seen by comparing how far the cork was moved by balls of different weights.
• Visual aids such as a graph or chart (pictured above) are useful when identifying patterns. The data recorded onto the chart clearly indicates that in all three weights of the steel balls, the cork is pushed further as they are dropped from higher heights, giving each line an upward pattern. Furthermore, the greater the mass of the steel ball, the further the cork is pushed at each height.

## Comparison to scientific theories, models, or laws.

The conceptual flow for this investigation outlines the theories of energy transfer and conservation. The conceptual flow begins with motion being a form of energy. The faster a given object is moving, the more energy it has. This we know as speed. In a collision, motion of one object can transfer to motion of other objects. The amount of energy in the rolling ball can be quantified in terms of the amount of work the ball can do when it collides with an object in its path (a collision). Objects at higher heights have more energy than the same objects at lower heights. A ball released from higher on the ramp applies more force to an impacted object than a ball released lower on the ramp. The potential energy due to the positioning of a ball on a ramp is easily transformed into kinetic energy as gravity pulls the ball down the slope. This is the outline of scientific theories and models we want students to grasp at this point in their science careers.

## Teacher notes: What parts of this experiment we think may be challenging for students

Some students may have difficulty getting started with their data analysis. If this is the case ask them to focus on one size of ball only and to think about the energy developed by the ball from its three release positions. Then they should look at the other two steel balls in the same way.

## Teacher notes: What we should do as teachers to scaffold those parts

For students who need scaffolding, provide sentences frames such as,

"When objects collide, . For example, we found out that ."

Doing a demonstration of setup and procedure would be useful to ensure all students are on the same track

Moving the experiment to the floor gives students more space to accommodate their investigations.