The "Next Generation Science Standards" (NGSS) encourages educators to help kindergarteners formalize a big idea in physics: A push or pull can cause an object to begin moving, speed up, slow down, stop, or change the direction it is going (NGSS Lead States 2013). In this article, the authors share an exciting, classroom-tested…

Paul Hewitt's "Figuring Physics" in the Feb. 2016 issue asked whether it would take a larger velocity change to stop a satellite in a circular orbit or to cause it to escape. An extension of this problem asks: What "minimum" velocity change is required to crash a satellite into the planet, and how does that compare with the…

In the teaching and learning of physics, simulations have many applications. Simulations can help to illuminate concepts (such as the motion of electrons in electric or magnetic fields) that cannot usually be seen with the unaided eye, or to slow down things that happen over short time periods or at high speeds. They can also be used to help…

Races between moving objects are an engaging way to teach dynamics to introductory physics students. One standard example consists in racing hollow and solid cylinders as they roll down an inclined plane. Another striking demonstration is a race between two marbles on side-by-side tracks that start and end together, but with one track taking a…

An ice hockey player can strike a puck at speeds up to about 45 m/s (100 mph) using a technique known as the slap shot. There is nothing unusual about the speed, since golf balls, tennis balls, and baseballs can also be projected at that speed or even higher. The unusual part is that the player strikes the ice before striking the puck, causing the…

According to the Newtonian formula for a simple pendulum, the period of a pendulum is inversely proportional to the square root of "g", the gravitational field strength. Einstein's theory of general relativity leads to the result that time slows down where gravity is intense. The two claims look contradictory and can muddle student and…

In popular accounts of the time dilation effect in Einstein's special relativity, one often encounters the statement that moving clocks run slow. For instance, in the acclaimed PBS program "NOVA," Professor Brian Greene says, "[I]f I walk toward that guy... he'll perceive my watch ticking slower." Also in his earlier piece for The New York Times,…

A rattleback is a well-known physics toy that has a preferred direction of rotation. If it is spun about a vertical axis in the "wrong" direction, it will slow down, start rocking from end to end, and then spin in the opposite (i.e. preferred) direction. Many articles have been written about rattlebacks. Some are highly mathematical and…

The purpose of the study is to investigate the elementary education undergraduate students' understanding levels of one dimensional motion which they take in the compulsory general physics course in the second year, third term and instructors' predictions about the students' responses. The study is a descriptive study. The data of the study were…

How far, in space, can we see? And can we see an object whose Hubble recessional velocity exceeds the speed of light? Maybe you've thought about these questions before, or perhaps you've seen them discussed in the literature or mentioned in the media. With the recent popularity of inflation and Big Bang cosmology, they're hard to avoid. The…

The speed of light is a fundamental characteristic of the universe. So many processes are related to and dependent upon it that, if creationist claims were true, the universe would be far different from the way it is now. The speed of light has never been shown to vary based on the direction from which it was measured. (PVD)

Describes the construction of a demonstration apparatus to illustrate the law of strings by using the light from a television screen to slow down the apparent motion of the waves of a string. (MDH)

Young students are familiar with the observable effects of force and motion but may not have considered the many varieties demonstrated in simple ways every day on the playground. A force is simply a push or a pull. A force can make an object move, move more quickly, change direction, slow down, or stop. Forces cannot be seen but their effect can…

When watching a small child with a toy car, it is seen that interest in motion comes early. Children often suggest speed through sounds such as "RRRrrrRRRooooommMMMmmmm" as the toy car is made to speed up, slow down, or accelerate through a turn. Older children start to consider force and motion studies in more detail, and experiences in school…