Physics Applications: Force

Force

Some of the most important details to keep track of in the creation of the Cataportal are the forces being applied to its arm, balloon, and self.

First off, let's observe the equation for Force:

F = ma

where F is Force in newtons,

m is mass in kilograms,

and a is acceleration in meters per second squared

With this kind of logic, it's alright to call weight a force since Earth is something with mass that pulls other somethings with mass towards it with acceleration, resulting in the FORCE of gravity. Thus, the equation for weight is:

W=mg

where W is weight in newtons,

m is mass in kilograms again,

and g is gravity in meters per second squared.

On Earth, g varies from place to place from a variety of factors, like the contents of the crust or distance from the equator, but it can still be estimated as 9.81 meters per second squared no matter where someone is. That would make our eight counterweights (12.5 pounds) about 55.6 newtons.

For our 55.6 newton weight (labeled here as M1) to jettison the projectile (labeled as M2) at a sufficient speed, it must hold more mass than M1 times the projectile's arm length (L2) over the counterweight's arm length(L1), and then some.

To increase the range, one can either add more mass to M1, or increase the difference between L2 and L1.

After we reach the right speed, we need the right release at the right angle at the right time. Our catapult uses a slanted hook on the end of the L2 arm to force the catapult to release when a certain accumulation of inertia is reached. Once inertia and acceleration reach a value high enough, one of the ropes slips off from the metal rod within the swinging arm, thus releasing the ball.