PHYSICS - SIMPLE MACHINES - II

Lever

     A lever is a simple machine made with a straight bar that moves on a fixed point called a fulcrum.  All levers have two parts, the bar and the fulcrum.  The longer the lever is, the less force will be needed to move the load. 

     The load and the force move in opposite directions.  Notice that as the hammer is pulled down, the nail moves up.

Examples of Levers
The tab is a lever used to open the can.	The screwdriver is being used as a lever.	The handle on the pump is a lever.
The can opener is a lever.	The bottle opener is a lever.	The shovel is a lever.

Wheel and Axle

     A wheel and axle is made from a wheel that turns on a center post.  The larger the wheel is, the less force will be needed to move the load.  There are two parts to this simple machine, the wheel and the center post called the axle.

     The force moves in the same direction as the load.  Notice that in the picture, the force pushes in the same direction that the skateboard is moving.

Examples of Wheel and Axles
Skates use wheel and axles.	We use a wheel and axle to reel in the fishing line.	Wheelchairs use wheel and axles.
The knob part is the wheel.  The axle connects the two knobs.	The steering wheel is a wheel and the axle goes into the steering column.	Skateboards use wheel and axles.

Inclined Plane

     Any slanted surface is an inclined plane.  A ramp is the most common type.  A ramp is higher at one end than at the other.  The longer the inclined plane is, the less force will be needed to move the load.  The only part of an inclined plane is the slanted surface.  

     The load and the force move in the same direction.  Notice in the picture that the force is pushing the lawn mower in the same direction it is moving.

Examples of Inclined Planes
An inclined plane lifts the front of this car.	A long inclined plane equals the four steps.  The ramp goes up, turns and continues.		A short ramp is needed to equal these two steps.
Inclined planes make our work easier.		An inclined plane is used to lift this heavy wheelbarrow into this trailer.

Wedge

A wedge is made by putting two inclined planes together.  They come together to form a V-shape.  A wedge may be used to lift or pry apart heavy objects.  A wedge can also be used to stop an object from moving.   A wedge has only one part.       The force and the load move in different directions.  In this picture, as the force moves the ax down, the load (wood) breaks apart and falls to the sides.

Examples of Wedges
The blade of a knife is a wedge.	Each blade of the scissors is a wedge.	The sharp edge of an ax is a wedge.
The sharp edge of the shovel is a wedge.	A door stop is a wedge that stops the door from moving.	A wedge called a chock stops the car from moving.

Pulley

     A pulley is a wheel with a rope around it.  The rope fits into the groove on the wheel.  The larger the wheel is, the less force will be needed to move the load.  There are two parts to a pulley, the wheel and the rope. 

     The load and the force move in opposite directions.  As the rope is pulled down, the flag goes up.

Examples of Pulleys
Pulleys are used to open and close curtains and blinds.	A pulley is used to make this ladder longer.	A pulley is a grooved wheel with a rope around it.
Pulleys are used for exercise, especially in hospitals, to help patients grow stronger.	Pulleys are used to raise and lower sails on sailboats.	Pulleys are used to raise and lower flags.

Screw

     A screw is an inclined plane that is wrapped around a center post.  The longer the inclined plane is the closer the threads of the screw will be and the less force will be needed to move the load.  A screw has two parts, the inclined plane and the center post. 

     The force and the load move in the same direction.  As the force pushes down on the screw, the screw goes down into the wood.

Examples of Screws

Some screws have a sharp point and are mostly used on wood.
The faucet has threads to screw the hose on.
Some screws have a flat end.  We call these screws bolts.   Most bolts use a nut.

Many bottles and jars have screw on lids.

Bicycle tires have threads on the stem to screw the cap on.
Light bulbs have threads to screw them into sockets.

INVENTION AT PLAY

MORE EXAMPLES OF SIMPLE MACHINES

Add 3 or more simple machines in your notes from this module

draw, label & explain.  Use color!

DUE:  Wednesday 10/3

PHYSICS - WHAT IS PHYSICS? #1

OKAY! Let's start here...

So you're asking, what is PHYSICS?
Everything in the universe has an effect on every other thing. 

Physics is a science that relates to all other sciences: Chemistry, Biology, Geology, Astronomy, Meteorology, Engineering, etc. If you can name it, chances are physics is involved. 
Everything on Earth, everything in our solar system, everything in our galaxy, and everything in the universe moves and interacts, and forces play a big part in that. Physics studies those FORCES and interactions. 

Physicists study those effects.

Let's get started and look inside the physics of motion. 

Mechanics and Motion

Motion is one of the key topics in physics. Everything in the universe moves. It might only be a small amount of movement and very very slow, but movement does happen. Don't forget that even if you appear to be standing still, the Earth is moving around the Sun, and the Sun is moving around our galaxy. The movement never stops. Motion is one part of what physicists call mechanics. Over the years, scientists have discovered several rules or laws that explain motion and the causes of changes in motion. There are also special laws when you reach the speed of light or when physicists look at very small things like atoms. 

Speed it Up, Slow it Down

The physics of motion is all about forces. Forces need to act upon an object to get it moving, or to change its motion. Changes in motion won't just happen on their own. So how is all of this motion measured? 
Physicists use some basic terms when they look at motion. 

• How fast an object moves, its speed or Velocity, can be influenced by forces. 
• (Note: Even though the terms 'speed' and 'velocity' are often used at the same time, they actually have different meanings.) 

Acceleration is a twist on the idea of velocity. 

• Acceleration is a measure of how much the velocity of an object changes in a certain time (usually in one second). 
• Velocities could either increase or decrease over time. 
• Mass is another big idea in motion. Mass is the amount of something there is, and is measured in grams (or kilograms). 
• A car has a greater mass than a baseball. 

Simple and Complex Movement

There are two main ideas when you study mechanics. 
The first idea is that there are simple movements, such as if you're moving in a straight line, or if two objects are moving towards each other in a straight line. The simplest movement would be objects moving at constant velocity. Slightly more complicated studies would look at objects that speed up or slow down, where forces have to be acting. 

There are also more complex movements when an object's direction is changing. These would involve curved movements such as circular motion, or the motion of a ball being thrown through the air. For such complex motions to occur, forces must also be acting, but at angles to the movement. 

In order to really understand motion, you have to think about forces, acceleration, energy, work, and mass. These are all a part of mechanics.