Longitudinal Waves

For longitudinal waves, the direction of energy transfer is the same as the movement of the particles. Particles in such a wave hit one another (compress) in order to transfer energy on to the next particles.

Swinging Back and Forth

 From a young age, children are attracted to the magic of the swing - or should I say the physics of it. Although it is true that toddlers' forward motion is provided by their parents' pushing of the swing, older kids manage to increase the speed of their motion without any external force helping them. This is explained by the theory of the parametric oscillator. By raising his/her body at the lowest moment of motion and lowering themselves at the highest, the child manages to increase his/her momentum, thereby lengthening the arc traveled on each swing.

Mousetrap Car

It is possible to create a car out of a common household mousetrap. How you ask? By attaching wheels to the moustrap, the turn of the back axel, which initiates the motion of the car, can be caused by the snap of trap.

The Law of Inertia

Newton's first law states that an object has a certain inertia, which allows it to resist a change in its state. Mass is the measure of this inertia, and is measured in kilograms (if using SI units). As a result of this inertia, an object that is at rest will remain at rest, and one with a constant velocity will continue moving with that velocity, unless acted upon by another object.


Unless something moves this turtle, it will remain still until it chooses to move.

Analyzing Projectile Motion

"Flying Cat"

To better understand projectile motion, we can analyze its vertical and horizontal components separately. The main motion equations we can use to do this are V=V0 + at, X=X0 + V0t + 1/2at^2, and V^2=V^20 + 2a(X-X0). Each of these equations can be used in respect to either X or Y values. For example, the first equation can be used to find the Y component (vertical component) of a projectile motion: Vy= Vy0 + ayt. *Also, in such a case, ay would actually be the acceleration due to gravity, or -9.81 m/s^2.