Tuesday, May 24, 2011

Boy Meets Physics




Newton's second law of motion states:

" A body of mass m subject to a net force F undergoes an acceleration a that has the same direction as the force and a magnitude that is directly proportional to the force and inversely proportional to the mass, i.e., F = ma. Alternatively, the total force applied on a body is equal to the time derivative of linear momentum of the body."


So, let's apply this to every day life.

Say your 15 year old son and his buddy Tim somehow get their hands on an old, broken down mower back in March. They remove the blades and mower deck and any other extraneous components and discard, a.k.a, toss them aside in the yard and later have to be cajoled, threatened, bribed, roped into disposing of said items properly.

Over the next two and a half months they tinker, bragging they are going to get it running so they can ride around and have some fun. The parents wonder out loud, pointedly, how they will pay for the gas for said mower, but the two teenagers shrug it off since it is so far in the future it doesn't concern them.

Then yesterday, after much tinkering, recharging of batteries, pilfering parts from certain parents without permission, and using of tools that don't belong to them, they actually get the thing started.

It doesn't sound pretty, but hey, it's working!

The brakes and the clutch are set up a bit because the thing hasn't moved in the two years previous to their owning it, but that doesn't stop them.

What does Newton's law of Motion have to do with it? Well, it seems to go hand in hand with Murphy's Law... that "the stupidity of your actions is directly proportional to the probability that somebody saw you."

Oh yeah. I saw it. I wish I had it on film.

Benjamin was driving, and Tim was standing on the back of the mower, hanging on to the steering wheel with Benjamin in front of him.

So let's review the second law of motion, shall we?

" A body of mass m subject to a net force F (That would be Benjamin) undergoes an acceleration a that has the same direction as the force and a magnitude that is directly proportional to the force and inversely proportional to the mass,(That would the mower) be i.e., F = ma. Alternatively, the total force applied on a body is equal to the time derivative of linear momentum of the body.

That last part would refer to the brake/clutch mechanism suddenly kicking in unexpectedly, and Tim flying over Benjamin's head, slamming it into the steering wheel, and Tim going head over shoulder over the front of the mower.

Enter: The law of Reaction.

The result.

See for yourself.





Hard to believe the kid scored so high on his CAT's, isn't it?


(Please Note: The names in this little tale have NOT been changed to protect the NOT SO Innocent.)

No comments: