Lasagne or Spaghetti? The Pasta Cantilever Challenge

Introducing engineering concepts into the high school physics classroom can help students grasp the relevance of scientific knowledge to the real world. I love to do this through project-based assignments in which students have to apply their knowledge through design-based activities. And what better way to keep students engaged and on their toes than to include a challenge for the best design!

Which cantilever will support the required weight at the maximum distance from the table?

An excellent resource for design-based teaching is NSTA’s Beyond the Egg Drop: Infusing Engineering into High School Physics. This is where I found the idea for my students to design and build cantilevers with pasta. All the activities in this book present students with an engineering design challenge while reinforcing physics concepts. The pasta cantilever challenge fits well with lessons on forces and equilibrium.

The challenge for this activity is for students to design and build a pasta cantilever that supports the weight at the greatest distance from the edge of the table. To incorporate the design engineering process, we do this activity over two class periods. During the first class, students build a prototype that they can test and evaluate to see what factors affect the cantilever’s ability to support the required mass at the greatest distance from the table. This allows them to see what other groups have done. Then, during the second class they are ready to build their final cantilever and see who wins the design challenge.

Students and teachers love this design challenge because it is fun, incorporates active hands-on learning, is easy to set up and allows students to compete against each other while learning. All you need for the pasta cantilever challenge is pasta, string, paper, tape and a 50 gram mass.

We’ve developed a resource for this activity that is now available in our TPT store. The lab activity includes goals and instructions, sample grading criteria, and a set of pre- and post-lab questions. We hope you and your students enjoy the Pasta Cantilever Challenge!


The Mu of the Shoe

Going out to a holiday party? You will probably want to wear your fanciest shoes. Getting ready for a basketball game? To show off your best moves you’ll need to have a lot of friction out on the court. But which shoes will serve you best? To answer this question, you need to know….“the mu of the shoe”!

Once students have learned about Newton’s laws of motion and the different forces that affect the motion of objects, we spend extra time on the force of friction because it has so many applications to our daily lives. Friction is the force that allows us to move through our environment, change direction, and carry objects. But for a full understanding of the friction force, students also need to learn about the coefficient of friction, a measure of the amount of friction between two surfaces.

Students can easily determine the coefficient of friction in the classroom using their own shoes and a spring scale. If you’d like to try this with your students, our Mu of the Shoe Friction Lab is a guided activity in which students work in groups to determine the coefficient of friction between their shoes and the floor. Students first look at all the shoes in their group and make predictions about which shoe will have the greatest coefficient of friction. Next, they measure the weight of their shoe, and then they pull it across the floor at a constant velocity to measure the force of friction on the shoe. This fun activity gives students experience with collecting data, performing calculations, and exploring the relationship between the weight of the shoe, the friction force, and the coefficient of friction.

The Shoe Friction Lab is the latest resource available in our TPT store. Students will enjoy debating which shoes they think have the highest coefficient of friction and then testing their predictions. Check out my introductory video on the force of friction for a helpful supplement to student learning about this topic.

How Powerful Are You?

Active learning can literally mean getting your students up and out of their seats and engaged in physical activity. When teaching energy, work and power, there’s no better way to drive home the concepts than to get the students outside the classroom to practice what they’ve learned. That’s why I assign them an activity where they have to determine how much power their bodies can generate.

At this point students have already learned the difference between mass and weight, the meaning of the term ‘work’ in physics, and that power expresses the amount of work done per second of time. They are now ready to go out and do some work to generate power. All they need is a stopwatch, a set of stairs, and a ruler or tape measure to determine the height of the stairs.

Next, we go into one of the stairwells at our school. Working in pairs, students take turns measuring the time it takes for them to go up one flight of stairs. I encourage students to go at their own pace (it is not a race) but for many it turns into a competition to see who can get up the stairs the fastest. Do you think the fastest person will generate the most power? Remember, power is the rate at which work is done.

For the students who try to get up the stairs the fastest, there will not be much difference in their times. But because the students’ masses vary significantly, those with the greatest mass will probably be able to generate more power. Comparing the results is a great time to figure out how fast the students with a lower mass would have to go up the stairs to be as powerful as the students with a higher mass.

Your students will have fun running up a set of stairs and calculating the amount of power they can generate. Visit our TpT shop to access our free How Powerful Are You? resource and see all of our Energy, Work and Power products. While you’re there, check out our Energy, Work and Power bundle with a comprehensive set of materials suitable for most 7th, 8th and 9th grade science curricula.

Starting Middle School with Science Skills

What do you do to engage students on the first day of the new school year? Give a lecture? Probably not! Go over the class rules? Boring!

For my middle schoolers, I like to kick off the school year with a fun science activity that can be used to: 1) teach basic lab skills, (2) introduce a new topic, in this case density and (3) check students’ level of prior knowledge. Ideally the activity gets them out of their chairs, moving around the classroom and working in small groups.

Students will need data collection, data presentation, and data analysis skills throughout their secondary science education. A great way to help students practice these skills is with my Calculating the Density of Different Materials activity. Students work in groups to measure the mass of different volumes of rice and sand, create a data table and a graph to show the volume and mass results, and answer questions that require them to analyse their data.

This activity will engage your students in ‘active learning’ and teach them essential skills that are useful beyond the science classroom. It’s easy to set up and requires readily available materials: graduated cylinders, balances, rice and sand.

We’ve made this activity available as a free resource in our Teachers Pay Teachers store. Visit our TpT shop to access this resource and see the new chemistry and electromagnetism products we added over the summer. You can also click here to sign up for our mailing list. You’ll receive occasional updates about our resources along with three free physics puzzles.

End of Year Fun with Famous Scientists

Do you need an engaging end of year activity that will motivate your students to squeeze in a little more learning before the summer break? The Famous Scientist Cereal Box Project combines research, design, organisation, and presentation skills and is ideally suited for 7th to 9th grade students. My students love this assignment which gives everyone a chance to do well with a little effort and a lot of creativity.

I kick off the project with a group discussion about famous scientists. Who do they know and what do they know about them (besides Albert Einstein!)? Who would they like to learn more about and what kind of cereal should be named after them? I give the students a list of scientists to choose from, but allow them to select a scientist not on the list with my approval.

After selecting a famous scientist, students must redesign a cereal box so that it describes the famous person’s life history and contributions to the sciences. Each panel of the box must include specific items worth a set number of points. The students must research some of the items, such as biographical information, interesting facts, and relevance of the scientist’s contributions. The fun part is that students get to use their imagination for the other items, such as the cereal name and slogan, an activity or game related to the scientist, and a small prize that goes inside the box. To conclude the project, teachers may have the students present their finished cereal boxes to the entire class.

We have posted a free resource in our Teachers Pay Teachers shop with a detailed outline and grading rubric for the Famous Scientist Cereal Box Project. Here’s the link to access this resource: Famous Scientist Cereal Box Project

Storytelling for Secondary Science

Just a few years ago my school principal informed me that I was required to complete more teacher training. Then came the good news. I was being sent to Greece to attend The Mars Mission Summer School sponsored by the European Union’s Erasmus+ Program and the Space Awareness Project. What better place to think about new teaching methods than on the beach in Marathon, Greece.

Experimenting with learning methods that meet the needs of different types of students was something I had done throughout my teaching career. But I had never given my students storytelling assignments and I came away from my Greek summer school experience excited to give it a try.

Storytelling assignments are a fun, interdisciplinary method to help students learn concepts that are central to a given science unit and a great way to stimulate their interest in science. I give my 7th and 8th grade students a storytelling assignment as part of our unit on the solar system. The basic idea is for students to write a story about going to Mars and colonizing the planet. But before the story writing can begin, each group must develop their story world, its characters, their goals… and obstacles they will encounter.

Each group gets a piece of flip chart paper and several 5 x 7 inch index cards. On the flip chart paper they design their Mars headquarters which must include four different buildings and two vehicles used for traveling away from the base. Each building must have a name, a short description of its purpose and a list of its contents. The index cards are used to develop the story’s characters. Students draw a picture of their characters on the front of each card and then use the back of the cards to list the character’s qualities. This can include age, gender, profession, skills, strengths, flaws, likes, dislikes and any other qualities that are relevant to their mission.

The purpose of this preparation is to encourage the students to be creative and to spend time thinking about their story before they begin writing. Students will come up with some wild ideas, such as “Can I bring my dog with me on the trip?”

During our lessons on space science we discuss the similarities and differences between the planets, interplanetary travel and the specific characteristics of Mars as they relate to the students’ stories. Each story must incorporate at least three of the concepts that we have discussed in class, such as: the atmospheric composition of Mars, the high iron content of the soil on Mars, the length of a day on Mars, temperature variation at the surface of Mars and the time needed to travel from the Earth to Mars.

Finally the writing can begin…

NASA’s Mars for Educators website contains lots of lesson plans, resources and teaching ideas. Science storytelling is just one innovative approach to stimulate student interest in science. Your students may even surprise you and get inspired to pursue a space related career path.

Newton and Coulomb: Fatal Attractions and Fundamental Forces

Something that always fascinates me about physics teaching and learning is that the basic concepts are closely interrelated. If you can grasp the concepts of Newton’s laws of motion as applied to the acceleration of objects in one dimension, then this knowledge can be used to evaluate the motion of objects in a variety of situations, including the motion of charged particles in electric and magnetic fields.

Another case where the basic laws of physics are interrelated is in the realm of the very big and the very small. We see this in the example of Newton’s law of universal gravitation and Coulomb’s law.

Newton first published his law of universal gravitation in Philosophiæ Naturalis Principia Mathematica in 1687. The law states that the gravitational force between two masses is directly proportional to the product of their masses and inversely proportional to the square of the distance between them.

As an inverse-square law, this law is analogous to Coulomb’s law, first published in 1785 by French physicist Charles-Augustin de Coulomb. It states that the electrical force between two charges is directly proportional to the product of their charges and inversely proportional to the square of the distance between them.

Although the laws have important differences, the equations look similar when seen side by side:

Each law is used to describe the forces between two objects, two masses in Newton’s case and two charges in Coulomb’s. Each law also contains a constant. For Newton’s law the constant G is quite small (6.67 ・ 10-11 Nm2/kg2) because the force of gravity is very weak. For Coulomb, the constant k is quite large (8.99 ・ 109 Nm2/C2) because the electric force is relatively large. In fact, the force of attraction between two 1 coulomb charges that are separated by a distance of 1 meter is one thousand trillion times greater than the force of attraction between two 1 kilogram masses separated by 1 meter. That is a very big difference!

One important difference between the two laws is that the force between two masses is always attractive, while the electric force between two charges can be either attractive or repulsive. Watch my latest video for a brief explanation of the difference between the two laws. And post a comment if you have any questions!

A great way to increase student knowledge of Newton’s law of gravitation and Coulomb’s law is through PhET online lab simulations. Students have fun with these simulations and Step by Step Science offers the companion activities shown below for students to practice what they learn.

Resources Galore in 2022

2021 was another year of steady growth for Step by Step Science. With more than 500 YouTube videos and 100 resources in our Teachers Pay Teachers store, we have been able to support and enrich teaching and learning for so many of you during the pandemic. Our goal has always been to offer high quality, engaging science content to teachers and students. The biggest reward for us is the positive feedback we receive.

Whenever I feel so frustrated and beat myself down for not understanding something people like you renew and refresh my love for math and physics. Thank you for helping me see the logic in the solution process. Physics is so beautiful 🙂

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We avoid fancy marketing campaigns and gimmicks, but we also want to cultivate a closer relationship with our followers. That’s why we’ve decided to send out occasional email updates. We’ll be highlighting our different types of resources and offering some free teaching activities. The first issue of our Resource Spotlight is coming soon and you can receive three free physics puzzles if you sign up. We promise not to bombard your inbox and you can unsubscribe at any time.

Click here to sign up for our mailing list. Our first Resource Spotlight will go out in early February and announce a sale on all of our Optics resources. Find out more about the sale when you sign up. Step by Step Science wishes all of our readers and followers a successful year of science education. We’ll also continue to stay in touch through this blog.

Scaffolding Science Lessons

Getting ready to start a new topic in your instruction? Not sure where to begin or what prior knowledge students have? I like to start with an opening question. For my unit on energy, work and power I always ask, “What is the difference between mass and weight?” Most students can not come up with a suitable answer or they often say that they are the same thing.

That leads to the next question for my students, “What is your weight?” The common response is something like “60 kilograms.” “Really, your weight is 60 kilograms?”, I ask with a tone of disbelief. I let that question hang in the air for a few moments and then a hand will shoot up and a student will say, “No, that is their mass because the units are kilograms!” So then I ask, “What is weight?”

Tapping into prior knowledge is a good scaffolding strategy. Scaffolding has become a popular educational term for breaking a subject up into chunks. Whether the subject is English or chemistry, math or physics, students often learn best when the material is organized into progressively more complex or in-depth components.

After exploring students’ prior knowledge, I cover basic terms and concepts that students need to know to move forward in the lesson. To understand terms like mass, weight, energy, work and power, students will watch my YouTube video on The Basics and then answer a few questions. Next, they complete a matching or puzzle activity that requires them to think about how the terms are used in the scientific world. Including an interactive exercise at this stage both engages the students and complements textbook learning. Now the class is ready to step up to the next scaffolding level.

The end goal of this unit is that students understand what is meant by the term conservation of mechanical energy. But to successfully reach this highest level on the scaffold, students must first have an understanding of all that leads up to it. This includes questions like how to change the potential energy of an object, how to increase the power output, and of course, what is the difference between mass and weight? Not only must students be able to use the equations to calculate the necessary values, they must also have a conceptual understanding of the physical conditions that affect the outcomes.

To help your students achieve mastery of these topics, I have created a series of products that are available from my Teachers Pay Teachers store. Each product includes explanatory notes, a set of exercises with an answer key, and two presentations to use for instruction. At the top of each set of exercises is a link to my Step by Step Science YouTube videos that students can watch for review. These products are also available in a discounted bundle and are a great resource for distance learning.

Scaffolding physics topics is a valuable approach that allows students across different grades and ages to master key terms and concepts before developing a broader base of subject knowledge. This methodical approach to teaching and learning is what Step by Step Science is all about.

Educational Evolution in the Sciences

More than 20 years ago I stepped into my first classroom. Before me sat rows and columns of students patiently waiting for me to teach them something. Today when I go to school things look pretty much the same. The science curriculum has changed little over the years and I still need to cover everything from Newton’s laws of motion to kinematics and electromagnetism. I still stand in front of class and teach, but my teaching style has evolved over the years. Nowadays I strive to motivate my students to become independent learners who can dive into problems and solve them on their own.

Demonstrations, interactive activities and lab work have always been at the heart of my teaching, but in recent years I have further refined my student centered approach. One of the ways that I have done this is through the use of computer simulations from PhET Interactive Simulations. Using these simulations and the guided-inquiry materials that I have developed, students discover for themselves the relationship between many physical parameters.  

Before I lecture on the topic of simple harmonic motion, students complete the online Period of a Pendulum Lab. Using this simulation students can learn on their own what physical characteristics affect the period of a pendulum. Students enjoy working with the simulations because they are visual, easy to use, interactive, and give reliable results that can be easily checked and repeated. In my experience, students are more likely to remain focused when using these materials than listening to one of my lectures.

Online simulations reflect the growing role of technology in education. Students and teachers communicate through computers, materials are made available through learning management systems and students have access to an infinite amount of instructional content from websites like YouTube and many others. But, as Derek Muller says in The Most Persistent Myth, technology will not revolutionise education. Education is still based on the social interaction between teachers and learners. Teachers must inspire, challenge and excite students, as well as make them accountable for learning. This is the part of teaching that inspires me to continue after more than twenty years in the classroom.