Chapter 4a

The Laws of Motion

Newton’s Laws, Gravitation, Mass, Weight, Tides

The book that revolutionized physics!

Demos to Prepare:
Bring a bunch of Grapes.

For Law of Inertia:
Mass on table roll, slide, accelerate.
SLV Car on Highway 9.
Nail in floppy board.
Mass between two springs jerkatory action.
Back of Bus device.
Clear the table.
Golden gate leap = splat!.
Hoop & Coin trick.
Inertial guidance stuff.
Mass on string with hammer to yank the doodle.
Cup of water spin (do you really believe in physics?).

For Law of Acceleration:
Spring balances.
Grapes of Galileo.

For Law of Action-Reaction:
Walking across the floor.
Balloon rocket.
Two liter methanol rocket!
Wild hose on the loose.
Cannon kicking.
Spring balances together.

Clear the Table & Eggs Inertia Videos:

Galileo's demonstration of inertia and why the earth appears not to be moving relative to us, Video:

Is this possible AT HIGH SPEED?”

Certainly it can be done at low speed and using trick photography make it look fast.

For example, suppose the truck is moving at 100kph and the car at 105kph.  Relative to the truck, the car is moving at only 5kph.  BUT the tires are spinning at 105kph when they engage the ramp.  That’s a lot of rotational kinetic energy to dissipate in a short distance!  Kinda like airplane wheels hitting the tarmac.

Then when the car backs down the ramp, its wheels are turning relative to the truck at 5kph and they are turning BACKWARDS relative to the road which is moving at 100kph.  It’s hard to imagine that the drive train and whatever else could handle a shock like that.

I asked the Mythbusters to try this AT HIGH SPEED, and they did. It worked with careful stunt driving.

Test Run Video:

Note that the snow balls are shooting tangentially to the wheel!

Coriolis Explained

Coriolis Demonstrated

The Coriolis Cat & Dog Videos:

These show that the direction of rotation in small systems depends upon local conditions, not the Coriolis Effect which needs a large system like air masses, ocean currents, and tornadoes.

The Coriolis effect on a Hurricane causes it to rotate counterclockwise in the northern hemisphere, Video:

Demos of the Law of Acceleration:

Spring balances accelerating different masses.
Grapes of Galileo all accelerating together when dropped.

Low friction devices such as air and dry ice pucks allow Newton's Law of Acceleration to be tested with very small forces.

What happens when an irresistible force acts upon an immovable object? Sheeesh! Well how about a very weak force accelerating a very large mass if friction is negligible? a = f/M. Video, a flea accelerates a five kilogram mass!! WOW!

Or a man accelerates a ship with his teeth! Video:

Demos for Law of Action-Reaction:

Walking by pushing on the floor
Balloon rocket
Fueled rocket.
Wild hose on the loose.
Cannon kicking
Spring balances together read the same.
Two liter methanol rocket! WOW!

The Law of Action-Reaction Videos:

And the firing of a compressed air cylinder rocket. There is an unbalanced forward vector at the front of a rocket. Video:

The Bottle Rocket in action-reaction! Video:

Can a cowboy be blown away by a bullet in the old corral? Video:

Big Fire Hose Action-Reaction lifts a car! Video:

Air Cannon kicks back awesomely!

The acceleration of Gravity is 9.8 meters/sec/sec. Video:

The Inertial Balance measures mass independent of gravity. Video:

More on the Opposite Tide

Here Endeth Chapter 4a