Kinematics tells us how bodies move, but it doesn't tell us why bodies move. Under dynamics, the concept of force is introduced to explain why there is motion. You can picture a force as either a push or a pull from something else. The objects can be touching, like when you push on a door, or they can interact in some other way, such as the Earth's gravity pulling you downwards.
The most important equation to remember in dynamics is F=ma, where F is the net force on an object. (Also known as Newton's second law) This will help you to to solve for the motion of the body using the information you already know. Try the explorations below for more information on this fundamental concept of physics.
Dynamics






An Atwood Machine is a simple device consisting of an ideal pulley and two masses connected over the pulley by an ideal string. The problem is to find the acceleration of the system and the tension in the connecting string given the two masses. The problem will first be solved numerically with masses of 3 kg and 5 kg, then a general solution will be developed. 



Updated 8/1/99


Dynamics






Buying your first car? Are you sure you're fully prepared to handle all the information that's about to be thrown at you by the car salesman? Well, here's a tip: Don't believe a salesman that promises that your new car has an acceleration any greater than 10m/s^2 , no matter the engine size. Why, you ask? Let's find out! 



Updated 7/20/99


Dynamics






The purpose of this lab was to determine the velocity of a penny that is dropped off the top of the Empire State Building just before it hits the ground. Although this problem may at first seem extremely simple, it changes if we introduce air resistance. For a problem like this, we are not looking for a numerical solution, but rather general observations on a graph. 



Updated 7/20/99


