Thursday, April 25, 2013

The laws of physics: something I just made up one day to torture my children.

Back when we were figuring out how many kids we wanted to have, we were using factors like money, time, housing, and wear and tear on the uterus to make the decision. Here’s the factor we should have used: HOW MANY CHILDREN WILL I HAVE TO TEACH HOW TO DRIVE….

It’s Screamapillar’s turn to try to kill me. I sit there in the co-pilot seat, completely powerless. Never in my life have I wished for a “chicken brake” more.

She accuses me of “yelling” at her when she drives. It’s actually screams of terror. Screamapillar and Thing Two have been the most difficult cases, because they are VERY stubborn and are of the opinion that, although I have been driving for 31 years, I couldn’t possibly have any information of value to offer them. They know it ALL and don’t need instruction. I dread the driving.

The part that is particularly galling is that they think that the laws of physics are something I made up. ‘Cause yeah, I’m just mean like that.

Let’s take a closer look at physics as it applies to teenage drivers!

Every body continues in its state of rest, or of uniform motion in a straight line, unless it is compelled to change that state by forces impressed upon it.
- Newton's First Law of Motion, translated from the Principia's Latin

This means that an object that is in motion will not change velocity (including stopping) until a force acts upon it. For example: If you wish to stop the car, and press the accelerator instead of the brake, your speed will actually increase. And your mother will scream.

The acceleration produced by a particular force acting on a body is directly proportional to the magnitude of the force and inversely proportional to the mass of the body.
- Newton's Second Law of Motion, translated from the Principia's Latin

This is pretty self explanatory: The more you press the accelerator, the more gas is transferred to the engine, the faster the car will go and the more your mother screams.

centrifugal force
an outward force on a body rotating about an axis, assumed equal and opposite to the centripetal force and postulated to account for the phenomena seen by an observer in the rotating body.

This one applies to turning: the faster you make the turn, the more forces are applied pushing the vehicle away from the direction of the turn. This usually results in bonking your  mother’s head on the passenger side window (which has more to do with the First Law actually), resulting loss of control of the vehicle and your mother screaming.

And no, no matter how many times you scream it at me, you do NOT “accelerate into a turn.”

Newon's Third Law: For Every Action there is a Reaction

 What does Newton's Third Law tell us?

(found HERE and edited by mommy)
Newton's third law tells us that when you push against something it pushes back on you with an equal and opposite force. Newton's 3rd law is the law of action and reaction. It tells how forces interact with each other. The forces are the action force and the reaction force. There will be a reaction force even if the object is non-living (or was living before you killed it).

Here are 5 examples of action and reaction forces: 

1.When you push on a wall the wall pushes back on you hit the garage door the garage door hits you. 

2. When you walk on the the ground, you push the ground and the ground pushes you run into the mailbox the mailbox runs into you.

3.When the bat hits the ball the ball hits the bat car plummets from a cliff into the ground the ground hits you 

4.When your finger touches your nose your nose touches your finger overcorrection causes you to plow into a telephone pole, the telephone pole plows into you.

5. When you push on a table the table pushes on you  smash into a parked car, the parked car smashes into you. 

Kinetic energy is a form of energy that represents the energy of motion. 

Kinetic energy is what makes you hit the oncoming car harder after you have failed to overcome centrifugal force because you ignored the Second Law. You mother won’t be screaming anymore because she’s dead.

But that’s okay, because there is no such thing as physics!

I quit teaching. But she still needs to learn to drive. Any volunteers?

1 comment:

Kat said...

OH, do I hear you completely. We just got through with this phase and it is actually official as of last week, however, it is still one of the scariest things I have done in my life. Luckily I have 10 years to recover before I'll have to do it again. :)