Newton’s Second Law of Motion or...

Does my ass make this bike look small?


Newton’s second law of motion states; Acceleration is produced when a force acts on a mass. The greater the mass (of the object being accelerated) the greater the amount of force needed (to accelerate the object).


This one really needs no interpretation but for those who were actually worse students than I, here are a couple of practical applications.

Like most teenagers of my time I operated in a different time relativity continuum than my parents. That is to say, what they wanted me to do right now, I would get to, eventually or not at all if I thought they had forgotten about it.

One evening after dinner my sisters washed the dishes and bickered while my brother held the bathroom hostage and read another chapter of his Luke Short western. My parents sat on the porch enjoying the rhythmic clanging of the hammer as I tried to beat the dents out of the door of Dad’s truck. The truck was an old International pickup and the dents were caused by the front wheel of my motorcycle. I had foolishly been practicing clutch control. It should be obvious that I needed more practice.

The girls called out that they were finished and Mom told me to go inside and take out the trash. I suppose that I must have sighed in exasperation as 13 year olds often do. Dad took exception to my attitude and strongly suggested that I get my ass in gear. I seem to recall mumbling, “If you don’t like the gear my ass is in now, you are going to hate the other choice”.

I don’t know what force propelled Dad from the porch to the driveway but, I do know what caused my sudden acceleration toward the kitchen. That was the amazingly accurate placement of his logging boot directly between the cheeks of my already ample butt. Acceleration was virtually immediate due to the amount of force acting on the mass of said ass. Lesson learned.

The second example is more directly related to my lifelong interests in motorcycles. At age 16 I was an aspiring motocross racer. I had traded the old 100 Twin Yamaha for a Yamaha 360 MX. But, here again, I was plagued with the time relativity problems of my early teen years. I was slow. Of course, I rationalized my slow starts by telling everyone that there was no point in joining the crowd at the first turn and crashing, so I just killed the bike at launch time and let everyone get strung out before I joined the fray.

Toward the end of the season I had given up any thought of actually winning a race. If I could only beat the one armed kid on the Suzuki I would be happy. Even that hope was dashed in the final race of the season when the duct tape and baling wire holding the clutch lever to the handlebar fell off during the first moto and I had forgotten to bring more of either.

Then my friend suggested that I ride his brand new Honda 125 Elsinore. I laughed because I was racing in the open class for bikes over 250 cc’s. Keep in mind that this was in 1973 in western Montana and that none of us had ever seen a two stroke Honda before that time. My buddy was a novice and had never raced but, his folks had money and he had a shiny new bike that scared the crap out of him.

After I was caught trying to steal a hose clamp for my clutch lever off the one armed racers Chevy pickup I relented and said that I would ride the Honda if no charges were filed. The one armed guy wanted to see the fat guy on the little bike get run over. So did everyone else. The cops took the handcuffs off and I got ready to ride.

I imagined I heard the Elsinore groan as all 240 pounds of me climbed aboard. I could feel my ears turning red inside my helmet as the crowd laughed and pointed at the Shriner clown on the mini-bike. All I needed was a fez with a tassel.

The tiny two stroke shrieked as I held the throttle wide open with the front tire against the gate. No need to kill this bike to hang back from the crowd to the first turn, I would be lucky to get there before I was lapped, or so I thought. The gate dropped. I popped the clutch.

Somewhere, deep inside that little engine, an atom split. An atomic bomb went off between my meaty thighs. I screamed. And held on. The knobby tire hooked up in the dirt and we launched. Down the straight that little bastard shrieked like a berserker headed to battle. I shrieked like a little girl. And held on. Somewhere before the first corner I finally got my feet on the pegs and speed shifted to second while standing on the rear brake. That would have worked better if I had rolled off the throttle. The bike screamed and the back tire slid out as the brakes locked up. Then the nuclear reactor overcame the brake in a cloud of blue smoke, the rear tire caught just as I dabbed the dirt with my left foot.

The only bike ahead of me into the turn was an old Bultaco. I had a bird’s eye view of it as I high sided and was launched over the top of him. The rider’s eyes were the size of dinner plates as he looked up and watched me fly. They got even bigger as I landed directly in front of him. The Bultaco went airborne after using me for a ramp and exited the track.

I rolled into a ball like a possum and waited for the next collision with my eyes closed. It never came. I heard crashing, screams of pain and some new curse words. As silence settled over the track and the crowd held a collective breath, I opened my eyes. The atomic bomb had exploded. Bikes and parts of bikes lay strewn everywhere. The Elsinore was dead.

My friend sat beside the track and wept as I scoured the dirt gathering all the pieces of his bike. I borrowed empty beer cases from the spectators and loaded the parts into them. I lightheartedly suggested that we bury them in the infield. He stopped sobbing as I bent to retrieve the shift lever. The force of a boot against my ass accelerated me face first into the dirt. It reminded me of something but I wasn’t sure what. Then I got it. Newton got it right.