Click on the picture field below.
Click on the radio buttons to change the ** x-** and

See the notes below.

This animation demonstrates projectile motion with no air resistance using various accelerations in the x and y directions.

The buttons at the bottom control the x-acceleration.
The button between the square brackets marks ** zero**
x-acceleration. Buttons to the

** Negative** x-accelerations point to the

The buttons on the right side control the
y-acceleration. They work much like the x-acceleration buttons with
** positive upward** pointing y-accelerations
increasing

To demonstrate normal projectile motion, set the x-acceleration to zero, since gravity does not pull horizontally, and set the y-acceleration to some negative value.

To demonstrate motion without gravity, set both x- and y-accelerations to zero. Of course, you will get fireworks with straight trajectories.

Negative gravity could be simulated with zero x-acceleration and a positive y-acceleration.

Isaac Newton's laws of motion
explain that accelerations are caused by forces.
The ** direction of the acceleration** is in the

One could, therefore, imagine the radio buttons to be controlling the
** direction of the
force** on the fireworks. One could think of this as if there
were

One could further imagine the above area to be a controllable **
constant
force field** through which a batch of effected particles is randomly thrown.