Visual Quantum Mechanics Teaching Guide - Activity 1 - Energy Diagrams

Oct 25, 2026

A teaching unit introduces energy diagrams as a powerful way to describe motion using energy rather than forces and acceleration. It contrasts classical and modern physics and motivates quantum mechanics as the framework for understanding atomic and subatomic processes. Activity 1 guides learners to construct potential energy diagrams for a toy car using magnets, then use observations to sketch speed and kinetic-energy graphs versus location. The unit emphasizes qualitative analysis, approximate sketches, and how friction alters energy curves compared with frictionless cases.

LanguageEnglish

CategoryTechnology

FormatPDF

Pages31

Reading Time1 h 18 min

AccessFree to download

Activity 1

Energy diagrams and motion

Potential energy diagram setup

Speed and kinetic energy sketches

Frictionless total energy concept

| potential ENERGY | Visual Quantum Mechanics Teaching Guide | | --- | --- | diagrams ACTIVITY 1 Energy Diagrams --- Attraction Goal Changes in energy are a good way to describe an object’s motion. Here you will construct energy diagrams for a toy car and learn how these diagrams can be useful. This technique will prepare you for similar uses of energy diagrams in quantum physics. In general terms physics can be divided into two broad categories-classical physics and modern physics. When we use modern physics to explain a phenomenon, we are using concepts that trace their origin to the quantum revolution that began in the early part of the 20th century. Classical physics is everything else. These two branches of physics share many concepts such as energy, momentum, forces, and conservation laws. They differ fundamentally in the concepts and models, which are used to describe the very small. To gain understanding of the processes taking place at atomic and subatomic levels, you need the help of quantum mechanics. The objective of the Visual Quantum Mechanics units is to introduce you to some aspects of this relatively new way of thinking and, thus, to learn how we know about very small objects such as atoms and molecules. In quantum mechanics the concept of energy is frequently used to help us describe events and motion. Instead of describing changes in motion in terms of forces and accelerations, we use changes in energy. A convenient way to describe changes in energy is to sketch a graph of the value of an object’s energy at various locations. When we create such a graph for energy, we call it an energy diagram. Using energy to describe motion is somewhat different from the typical approach. However, it is a very powerful technique that can be used for both small and large objects. To prepare you for learning about atoms and other small objects you will first describe the motion of a toy car using potential energy diagrams. You will see that you will be able to describe the motion of a moving object without actually seeing that object or its motion. All you need to know is the energy. 1A-1 An example of a potential energy diagram is shown in Figure 1-1. On the horizontal axis is the location of the car while the vertical axis shows the value of the potential energy at each location. It shows us how the potential energy changes along the path of the car. The potential energy is highest for locations between 0 and 0.1 meters, is 0.1 joules, and rises to an intermediate value for 0.2 to 0.3 meters. We shall see we can learn a lot about the car’s motion from this diagram. 0.00 0.05 0.10 0.15 0.20 0.25 0.30 Location (meters) Figure 1-1: A potential energy diagram for a toy car . The potential energy varies with the location of the object. This energy change can arise from a variety of interactions including elastic, gravitational, chemical, etc. In this unit, the potentials are generated with the help of magnets. However, the interactions between atoms and nuclei are of different origin. Therefore, the comparison with the atom that you will attempt later on will only be concerned with the shape of the potential energy curve, not with the origin of the interactions. In these four activities you will arrange magnets along a track and observe the interaction between these magnets and a magnet on the car. By changing configurations ofthe magnets along the track you will obtain potential energy diagrams of various shapes. In this activity you will arrange the magnets in attractive mode. The friction between the wheels of the car and the track is relatively high. If we were to account for that friction, it would have made the energy diagrams complicated. However, for the purposes ofour qualitative analysis we will try to think about what would have happened if the friction acting on the car were very small. In this activity we will frequently make approximate sketches of the energy of the toy car. As

FAQs

What is the purpose of energy diagrams in describing an object’s motion?

Energy diagrams describe motion by tracking how an object’s energy changes with location, instead of focusing on forces and accelerations. This helps learners use the technique for later applications in quantum physics.

How is a potential energy diagram for the toy car constructed in Activity 1?

Learners arrange magnets along a track in an attractive mode and observe how the car’s interaction energy varies with location. The diagram’s curve shape is the key focus rather than the interaction origin.

Why do the kinetic energy and total energy graphs differ when friction is ignored?

With friction, kinetic energy decreases because energy goes into overcoming friction. If friction were absent, the kinetic energy versus location sketch would be a straight line and the total energy (potential plus kinetic) would remain constant.

Oct 25, 2026

Uploaded by AfterMidnight