Watch alpha particles escape from a polonium nucleus, causing radioactive alpha decay. See how random decay times relate to the half life.
Watch alpha particles escape from a polonium nucleus, causing radioactive alpha decay. See how random decay times relate to the half life.
Los estudiantes aprenden acerca de la electricidad y el magnetismo mediante la construcción de altavoces
Aerogel, commonly called "frozen smoke," is a super-material with some amazing properties. In this lesson and its associated activity, students learn about this silicon-based solid with a sponge-like structure. Students also learn about density and how aerogel is 99.8% air by volume, making it the lightest solid known to humans! Further, students learn about basic heat transfer and how aerogel is a great thermal insulator, having 39 times more insulation than the best fiberglass insulation. Students also learn about the wide array of aerogel applications.
Students learn how nanoparticles can be creatively used for medical diagnostic purposes. They learn about buckminsterfullerenes, more commonly known as buckyballs, and about the potential for these complex carbon molecules to deliver drugs and other treatments into the human body. They brainstorm methods to track buckyballs in the body, then build a buckyball from pipe cleaners with a fluorescent tag to model how nanoparticles might be labeled and detected for use in a living organism. As an extension, students research and select appropriate radioisotopes for different medical applications.
The purpose of this lesson is to introduce students to the planet Mars. This lesson will begin by discussing the location and size of Mars relative to Earth, as well as introduce many interesting facts about this red planet. Next, the history of Martian exploration is reviewed and students discover why scientists are so interested in studying this mysterious planet. The lesson concludes with students learning about future plans to visit Mars.
The lesson begins with a demonstration introducing students to the force between two current carrying loops, comparing the attraction and repulsion between the loops to that between two magnets. After formal lecture on Ampere's law, students begin to use the concepts to calculate the magnetic field around a loop. This is applied to determine the magnetic field of a toroid, imagining a toroid as a looped solenoid.
Students design, build and test model roller coasters using foam tubing. The design process integrates energy concepts as they test and evaluate designs that address the task as an engineer would. The goal is for students to understand the basics of engineering design associated with kinetic and potential energy to build an optimal roller coaster. The marble starts with potential energy that is converted to kinetic energy as it moves along the track. The diameter of the loops that the marble traverses without falling out depends on the kinetic energy obtained by the marble.
In this activity, students discover the relationship between an object's mass and the amount of space it takes up (its volume). Students learn about the concept of displacement and how an object can float if it displaces enough water, and the concept of density and its relationship to mass and volume.
Students prepare for the associated activity in which they investigate acceleration by collecting acceleration vs. time data using the accelerometer of a sliding Android device. Based on the experimental set-up for the activity, students form hypotheses about the acceleration of the device. Students will investigate how the force on the device changes according to Newton's Second Law. Different types of acceleration, including average, instantaneous and constant acceleration, are introduced. Acceleration and force is described mathematically and in terms of processes and applications.
In the first of two sequential lessons, students create mobile apps that collect data from an Android device's accelerometer and then store that data to a database. This lesson provides practice with MIT's App Inventor software and culminates with students writing their own apps for measuring acceleration. In the second lesson, students are given an app for an Android device, which measures acceleration. They investigate acceleration by collecting acceleration vs. time data using the accelerometer of a sliding Android device. Then they use the data to create velocity vs. time graphs and approximate the maximum velocity of the device.
Students develop an app for an Android device that utilizes its built-in internal sensors, specifically the accelerometer. The goal of this activity is to teach programming design and skills using MIT's App Inventor software (free to download from the Internet) as the vehicle for learning. The activity should be exciting for students who are interested in applying what they learn to writing other applications for Android devices. Students learn the steps of the engineering design process as they identify the problem, develop solutions, select and implement a possible solution, test the solution and redesign, as needed, to accomplish the design requirements.
Students investigate the motion of a simple pendulum through direct observation and data collection using Android® devices. First, student groups create pendulums that hang from the classroom ceiling, using Android smartphones or tablets as the bobs, taking advantage of their built-in accelerometers. With the Android devices loaded with the (provided) AccelDataCapture app, groups explore the periodic motion of the pendulums, changing variables (amplitude, mass, length) to see what happens, by visual observation and via the app-generated graphs. Then teams conduct formal experiments to alter one variable while keeping all other parameters constant, performing numerous trials, identifying independent/dependent variables, collecting data and using the simple pendulum equation. Through these experiments, students investigate how pendulums move and the changing forces they experience, better understanding the relationship between a pendulum's motion and its amplitude, length and mass. They analyze the data, either on paper or by importing into a spreadsheet application. As an extension, students may also develop their own algorithms in a provided App Inventor framework in order to automatically note the time of each period.
Students analyze the relationship between wheel radius, linear velocity and angular velocity by using LEGO(TM) MINDSTORMS(TM) NXT robots. Given various robots with different wheel sizes and fixed motor speeds, they predict which has the fastest linear velocity. Then student teams collect and graph data to analyze the relationships between wheel size and linear velocity and find the angular velocity of the robot given its motor speed. Students explore other ways to increase linear velocity by changing motor speeds, and discuss and evaluate the optimal wheel size and desired linear velocities on vehicles.
Students are introduced to the classification of animals and animal interactions. Students also learn why engineers need to know about animals and how they use that knowledge to design technologies that help other animals and/or humans. This lesson is part of a series of six lessons in which students use their growing understanding of various environments and the engineering design process, to design and create their own model biodome ecosystems.
Antimatter, the charge reversed equivalent of matter, has captured the imaginations of science fiction fans for years as a perfectly efficient form of energy. While normal matter consists of atoms with negatively charged electrons orbiting positively charged nuclei, antimatter consists of positively charged positrons orbiting negatively charged anti-nuclei. When antimatter and matter meet, both substances are annihilated, creating massive amounts of energy. Instances in which antimatter is portrayed in science fiction stories (such as Star Trek) are examined, including their purposes (fuel source, weapons, alternate universes) and properties. Students compare and contrast matter and antimatter, learn how antimatter can be used as a form of energy, and consider potential engineering applications for antimatter.
The purpose of this video lesson is to expand the student's knowledge about enzymes by introducing the antioxidant enzymes that are intimately involved in the prevention of cellular damage and eventual slowing of the aging process and prevention of several diseases. Students will learn that natural antioxidant enzymes are manufactured in the body and provide an important defense against free radicals. The topic of free radical action is introduced, covering how they are constantly generated in living cells both by ''accidents of chemistry'' and also by specific metabolic processes.
This final lesson in the unit culminates with the Go Public phase of the legacy cycle. In the associated activities, students use linear models to depict Hooke's law as well as Ohm's law. To conclude the lesson, students apply they have learned throughout the unit to answer the grand challenge question in a writing assignment.
Does the real-world application of science depend on mathematics? In this activity, students answer this question as they experience a real-world application of systems of equations. Given a system of linear equations that mathematically models a specific circuit—students start by solving a system of three equations for the currents. After becoming familiar with the parts of a breadboard, groups use a breadboard, resistors and jumper wires to each build the same (physical) electric circuit from the provided circuit diagram. Then they use voltmeters to measure the current flow across each resistor and calculate the current using Ohm’s law. They compare the mathematically derived current values to the measured values, and calculate the percentage difference of their results. This leads students to conclude that real-world applications of science do indeed depend on mathematics! Students make posters to communicate their results and conclusions. A pre/post-activity quiz and student worksheet are provided. Adjustable for math- or science-focused classrooms.
Students explore Hooke's law while working in small groups at their lab benches. They collect displacement data for springs with unknown spring constants, k, by adding various masses of known weight. After exploring Hooke's law and answering a series of application questions, students apply their new understanding to explore a tissue of known surface area. Students then use the necessary relationships to depict a cancerous tumor amidst normal tissue by creating a graph in Microsoft Excel.