Physics Education

Unfortunately, owing to the abstract and counterintuitive nature of many of the elementary concepts in physics, the lecture method often fails to help students overcome the many misconceptions about the physical world that they have developed before undertaking formal instruction in the subject. In most introductory physics courses mechanics usually is the first area of physics that is discussed. Newton's Laws Of Motion , which describe how massive objects respond to forces, are central to the study of mechanics. Newton arrived at his three laws of motion from an extensive study of empirical data including many astronomical observations.

However, students frequently have preconceptions about the world around them that makes it difficult for them to accept Newton's Laws Of Motion . As an example Newton's First Law , also known as the law of inertia, states that, in an inertial frame, a body at rest will remain at rest and that a body moving at constant velocity will continue to move with the same velocity unless a net Force acts on the body. Many students hold the misconception that a net force is required to keep a body moving at constant Velocity . They know that to slide a book across a table a "push" has to be exerted on the book. However, they fail to take into account that there is more than one force acting on the book when it is being pushed across the table at constant velocity. In addition to the "push" being exerted, there also is a Frictional Force in the opposite direction acting on the book from the tabletop. When the book moves at constant velocity those two forces balance out (add vectorially) to produce a net force of zero.

In an Active Learning environment students might experiment with objects in an environment that has almost no Friction , for example a block moving on an almost frictionless air table. There they would find that if they start the block moving at constant speed, it continues to move at constant speed without the need for a constant "push". It is hoped that exercises of this nature will help students to overcome their preconceived ideas about motion.

GOALS OF PHYSICS EDUCATION RESEARCH

The primary goal of physics education research is to develop pedagogical techniques and strategies that will help students learn physics more effectively. Research often focuses on learning more about the common misconceptions that students bring to the physics classroom, so that techniques can be devised to help students overcome these misconceptions. A variety of interactive learning methods (sometimes also called Active Learning methods) and laboratory experiences have been developed with this aim.

ADDITIONAL EXAMPLES OF MISCONCEPTIONS IN PHYSICS

Heavy objects fall faster than light objects: Near the surface of the earth the Acceleration of an object due to the gravitational force is locally constant (approximately $9.8rac{m}{s^2}$ ). As a result, in the absence of air resistance, both heavy objects and light objects should fall at the same rate when dropped. However, many students when asked say that heavier objects fall faster than light ones even if air resistance is negligible. This is natural because if one drops a feather and a rock at the same time, the rock definitely will hit the ground first. However, in that case the upward frictional force on the feather from air resistance is nearly equal to the downward gravitational force, while for the falling rock the air resistance is very small compared to the gravitational force. The "penny and feather" is a classic demonstration that has been used to show students that light and heavy objects do fall at the same rate when there is no air resistance. This demonstration requires a vacuum pump to remove air from a glass or clear plastic tube that contains a penny and feather that can be dropped by quickly turning over the tube. A simpler demonstration can be done with an aluminum ball and a lead ball that are the same size. If they are dropped simultaneously, they will hit the ground at the same time.

When two objects with different masses collide, the force on the less massive object is larger than the force on the more massive object: Though Newton's Third Law says that the force exerted by the more massive object on the less massive one is equal in magnitude to the force exerted by the less massive object on the more massive one, many students believe the opposite. This common misconception is understandable because students know that when a very massive object (for example a railroad train) collides with a much less massive object (say an automobile), the less massive object usually is much more heavily damaged. However, the differences in damage are a consequence not of the forces being different in magnitude, but rather of the much different accelerations that parts of each object undergo in the collision. Newton's Second Law requires that ''F''=''ma'' so parts of the more massive object experiences much smaller accelerations than parts of the less massive object. While it is possible to directly measure the forces on each object in a two-body collision with strain gauges, many high school and introductory college labs don't have the equipment available to make such measurements. A somewhat simpler approach is to measure the change in Momentum for each of two rigid objects in a collision. The change in momentum is a measure of the Impulse , ''FΔt'', that each object experienced. Since the duration of the collision, ''Δt'' is the same for both, the change in momentum measures the magnitude of the forces involved.

	CATEGORIES ABOUT PHYSICS EDUCATION

	physics educationphysics education

	physics

	education

	education by subject

	science education

	APPAREL
	BABY
	BEAUTY
	BOOKS
	CAR TOYS
	CELL PHONES
	DVD'S
	ELECTRONICS
	GOURMET FOOD
	GROCERIES
	HEALTH & PERSONAL
	HOME & GARDEN
	JEWELRY
	MUSIC
	MUSIC INSTRUMENTS
	OFFICE PRODUCTS
	SOFTWARE
	SPORTING GOODS
	TOOLS & HARDWARE
	TOYS
	VIDEO GAMES
	SHOPPING HOME

	MORE SHOPPING...

Information About

Physics Education