Rubber Band Car

• Databot with accelerometer

• IOS/Android Smart Device

• Toy car or similar rolling object.

Overview

Background

What You Will Need/Prep

• Test your databot™ connection.

• You will be prompted to select
  and connect to databot™ each
  time you launch an experiment.

• If there are two or more
  databot™'s listed, the one
  closest to your device will be
  highlighted.

• Study the background
  information and terms and
  prepare to explore!

Rubber Band Car

Have you ever wondered how a simple rubber band
can make a toy car move? In this activity, you will
explore the fascinating relationship between energy
and motion. Using databot, you’ll measure how the
car moves over time, calculate its speed, and
analyze how far and how fast it travels.

Grades: Middle School

Time: 45 Minutes

Subject: Physical Science

Topics: Acceleration, Force, Kinetic
and Potential Energy

Motion occurs when an object changes its position
relative to a reference point. Such terms like speed,
acceleration, and distance are used to describe the
motion, and Newton’s three laws of motion help to
understand the behavior of objects in motion.

Motion happens when forces and energy come
together. Energy is what makes things move! It exists in
many forms, but two of the most important types of
energy in physics are kinetic energy and potential
energy. Potential energy is the energy stored in an
object due to its position or condition. Kinetic energy,
on the other hand, is the energy of motion, which an
object has when it is moving. These two forms of
energy are often transformed into one another.

An excellent example of the transformation of different
forms of energy is to use a rubber band to start a car.
When you pull back the rubber band, it stores elastic
potential energy—energy that comes from the band’s
ability to return to its original shape. The more you
stretch the band, the more energy it stores. When you
let go, this energy turns into kinetic energy, or energy of
motion, making the car speed across the surface. Other
real-world examples of energy transfer are archery and
catapults, which launch objects using stored elastic
energy.

• Install Vizeey™ on your
  Smart device.

• Rubber band (preferably of
  consistent elasticity).

• Measuring tape

• Graph paper or data graphing
  app

Important Terms

Learning Objectives

By completing this lab, students will:

• Visualize, collect and analyze data

• Measure acceleration of the toy car.

• Understand energy transfer: explain how elastic potential energy is converted into
  kinetic energy.

• Analyze the relationship between force, mass, and acceleration.

Acceleration: The rate at which an object’s speed changes over time.

Elastic Energy: The potential energy stored in a stretched or compressed object, such as
the rubber band, which can be released to do work.

Energy Transfer: The process by which energy moves from one system or object to
another (e.g., from the stretched rubber band to the moving car).

Force: A push or pull that causes an object to move or change its motion.

Kinetic Energy: The energy of motion. It increases as an object speeds up.

Newton’s Laws of Motion describe the behavior of objects in motion:

• • First Law: an object will stay at rest or move at a constant speed unless acted on
    by an outside force.

  • Second Law: the acceleration of an object depends on the force applied and its
    mass expressed in the equation F=m⋅a (Force equals mass times acceleration).

  • Third Law: For every action, there is an equal and opposite reaction.

Potential energy: the stored energy of an object due to its position, shape, or condition.

Speed: The distance an object travels per unit of time.

Velocity: Speed in a specific direction.

Through this hands-on activity, you’ll uncover the science
behind motion and explore how forces, energy, and speed
interact to make everyday objects move. Let’s dive into the
world of physics and see what the toy car can teach you!

Press this button to start the experiment.

• Acceleration graph

• Current acceleration

• You also have the opportunity to study
  the chart in more detail after it is
  created. To do this tap the two up/down
  arrows. Your data will open in a bigger
  “zoom” mode.

• By default you will be in Pan and zoom mode which allows you to move the data side
  from side to side with your finger or pinch to zoom in or out.

• To see the values at any point of the graph, you first need to press the “Pick data”
  button.

In order to work with the experiment you need to launch the Vizeey application and click on
+ in the upper right corner.

Then select “Add experiment from QR code” and scan the QR code prepared for this
experiment. Your experiment will appear in the list.

When you start the experiment you will be immediately
offered to connect to your databot. Make sure that
databot is enabled.

In this lab you will explore motion using
accelerometer. You will observe:

• Click on any point on the chart to see the values.

1. How does the distance the car travels depend on how much the rubber band is
   stretched? Will stretching the rubber band more make the car go faster?

2. What role does the car’s weight play in how far or fast it moves?

Consider how factors such as the amount a rubber band is stretched, friction, and a
mass of the car might influence the motion.

Part 2: Hypothesis

Part 3: Experiment Procedure

Preparation

Before starting the experiment, follow these steps to ensure everything is set up properly:

• Prepare the Surface: select a flat, horizontal surface for the toy car to move on. Ensure
  it is smooth and free from obstacles to allow for consistent motion.

• Attach databot: secure databot to the toy car. Depending on the car's design, you can
  use a rubber band or adhesive tape to attach databot firmly. Ensure it is stable and does
  not shift during the car's movement.

3. How does the type of surface affect the car’s motion?

Rubber band

Databot

• Set Up the Launch Platform

Depending on the available materials, there are two options for setting up the launch
mechanism:

Option 2: Pre-Made Launch Platform

Use a ready-made launch platform, such as
the one from a Hot Wheels toy set. These
platforms typically use a built-in rubber band
for launching and are pre-designed for easy
and automatic operation.

If you have access to such a platform, no
additional assembly is needed, making this
option more convenient.

Option 1: DIY Rubber Band Launcher

Install two supports to hold the rubber
band. These can be as simple as two
screws fixed firmly into the surface or a
similar structure.

Stretch the rubber band between these two
supports. The setup should resemble a
slingshot or crossbow mechanism, with the
rubber band providing the launching force.

By completing these steps, you’ll ensure the setup is ready for accurate data collection!

Screws

Rubber band

Databot

Screws

Side view

Top view

• Open the Vizeey app on your smart device.

• Turn on databot (using the small button on the left side)

• Tap on "Rubber Band Car" in Vizeey to load the experiment.

• You will be prompted to connect to databot.

  • Hint- if there is more than one databot in use, the one closest to you will be in blue!

  • A solid blue light on databot means you are connected.

• Use these icons at the top of the screen in Vizeey to start and to pause the
  experiment.

Note: Consistency is the key to accurate results. Make sure that the toy car always starts
from the same position.

• Start your experiment using:

• Place the car with databot on the start line.

• Release the rubber band - to make the car go while databot will record acceleration
  values.

Top view

Analyze the graph you have obtained and give answers to the questions:

• What does the highest point on the graph represent?

• What is your maximum acceleration?

• How long does the car accelerate before it starts slowing down?

• Why does the graph rise quickly and then fall gradually (or vice versa)?

• What does the slope of the graph tell us about the rate of change in acceleration?

• What part of the graph corresponds to the car’s motion slowing down due to friction?

You can get a similar data graph

This graph show you the maximum acceleration - at the moment the rubber band
was released, is 9.37 m/s² .

Part 4: Data Analysis

Example: 71.26 S - 71.16 S = 0.1 S

Part 5: Concept Questions

How does the energy stored in a stretched rubber band affect its ability to move the car?

What happens if you change the tension force of the rubber band?

How do you think the graph would change if a lighter or heavier car was used?

What does the shape of the acceleration graph tell you about the car's motion over time?

Part 6: Reflection

1. What factors influenced the acceleration and distance the car traveled?

2. Why does the car move faster when the rubber band is stretched more?

3. Can we use measurements like stretch distance to predict the car's motion?

• What force was applied to launch the car at maximum acceleration?

Using Newton’s second law , you can calculate the
maximum force exerted by the rubber band at launch if the car's mass is
known. You need to weigh the toy car together with databot.

Example:

Mass of the car: m = 79 g = 0.079 kg

Force applied by the rubber band: