Proceeding like Newton with a discrete time approach of motion and a geometrical representation of velocity and acceleration, we obtain Kepler's laws without solving differential equations. The difficult part of Newton's work, when it calls for non-trivial properties of ellipses, is avoided by the introduction of polar coordinates. Then a simple…

Students use the relationship between the speed of a ball and the time that a player has to react to it to understand uniform motion problems. Includes activity sheets. (Author/NB)

Explores strategies in the situation of a runner trying to evade a tackler on a football field. Enables the student to test intuitive strategies in a familiar situation using simple graphical and numerical methods or direct experimentation. (JRH)

A procedure for estimating the speed and distance of plane, assuming the speed of sound and the velocity of the plane are constant, is described. (KR)

A procedure for measuring the speed of light using the assumption that the frequency of light remains unchanged as it moves from one medium to another is presented. A laser with a known wavelength and frequency in air was used as a light source. (KR)

Presents a few examples of not-so-traditional problems that can be very helpful in teaching some particular concepts or approaches in physics. Problem sets include vector addition and vector components, reference frames, and choosing the right approximations. (JRH)

Describes the differential equation solution to the mechanics problem of the motion of a free mass subject to a harmonic force which can also be illustrated by a simple analogue computer. (SL)

Provides six problems to help students understand new concepts of force using situations they already understand concerning velocity, acceleration, and momentum. (MVL)

Provides a method of solving vector and force problems that is less complicated for the learner. Gives several examples concerning projectiles and inclined planes. (MVL)

Describes the graphing calculator as a new graphical approach to standard physics problems. Presents a collision problem to illustrate its use. (JRH)

Considered are parallel and perpendicular relative velocities and their effect on the minimum time it takes a boat to cross a river. (Author/MA)

Presents four examples of physics problems that can be solved with a graphing calculator. Problems included deal with motion, harmonic oscillations, sound waves, and blackbody radiation. (JRH)

Describes an activity that challenges students to apply their knowledge of motion to designing and constructing roller coasters. Emphasizes the processes students go through to communicate their ideas and the problem-solving skills they develop. (JRH)

An example of how a traditional activity on motion and acceleration can be adapted to the learning-cycle format is described. The three challenge statements given to students to solve are provided. The key learning-cycle steps of exploration, expansion, and extension are discussed. (KR)

Uses projectile motion to explain the two roots found when using the quadratic formula. An example is provided for finding the time of flight for a projectile which has a negative root implying a negative time of flight. This negative time of flight also has a useful physical meaning. (MVL)