Laws and the Discoveries

LAW vs. THEORYLaw: is a statement that describes what scientists expect to happen every time under a particular set of conditions.Examples: 1. Robert Boyle (1627-1691) - A law of gases which states that at

constant temperature the volume of a gas varies inversely with its pressure.

2. Mendel's Laws of Heredity - The law of segregation and The law of independent assortment

3. Isaac Newton – the Laws of Motion

LAW vs. THEORY• Theory: is a well-tested idea that explains and connects a wide range of

observations.• A theory is valid as long as there is no evidence to dispute it. Therefore,

theories can be disproven

LAW vs. THEORY• The Earth orbits the Sun (Heliocentric Theory) by Nicolaus Copernicus

• Living things are made of cells (Cell Theory) by Theodor Schwann, Matthias Jakob Schleiden, and Rudolf Virchow

• Matter is composed of atoms (Atomic Theory) by John Dalton

• The Earth's surface is divided into solid plates that move over geological time (Theory of Plate Tectonics) by J.T. Wilson

• The Theory of Evolution is the scientific explanation for how evolution occurred, past and present (Darwin)

Law and TheoryWord Map

What the Word Means

Word

Example Example Example Sentence

A Picture

The Law of Conservation of Energy• James Prescott Joule (1818-1889)• Born at Salford, near Manchester, England on

December 24, 1818.• From 1834-1837 he was taught chemistry,

physics, the scientific method, and mathematics by famous English Chemist John Dalton.

James Joules (cont.)

• In 1839, Joule began a series of experiments involving mechanical work, electricity and heat.

• 1843, Joule calculated the amount of mechanical work needed to produce an equivalent amount of heat.

• The principle of energy conservation involved in Joule’s work gave rise to the new scientific discipline known as thermodynamics.

Sir Isaac Newton

• English scientist, astronomer, and mathematician

• Born in December 25, 1642 - Died in 1727• Isaac Newton was raised by his grandmother. He attended Free

Grammar School and then went on to Trinity College Cambridge. Newton worked his way through college. While at college he became interested in math, physics, and astronomy. Newton received both a bachelors and masters degree.

• One day when he was drinking tea in the garden, he saw an apple fall to the ground. He started thinking about why it fell, and finally concluded that the same force which caused the apple to fall also kept the moon in orbit around the earth. This same force, gravity, also kept the planets in orbit around the sun.

• The apple incident led to his basic laws of motion.

Sir Isaac Newton (cont.)• His second discovery was about light and the properties of

light. He spent months in a darkened room doing experiments. He passed a beam of sunlight through a prism and discovered that the beam of light was broken down into different colors. His conclusion: something that appears green, such as grass, looks green because it reflects the green light in the sun and absorbs most of the other colors. (reflecting telescope)

• Newton's third great discovery was in the field of math when he developed a kind of math we call calculus. He was just 24 years old at the time.

Law of ThermodynamicsAccording to Newton's first law...

An object at rest will remain at rest unless acted on by an unbalanced force. An object in motion continues in motion with the same speed and in the same direction unless acted upon by an unbalanced force. This law is often called "the law of inertia".

What does this mean? This means that there is a natural tendency of objects to keep on doing what they're doing. All objects resist changes in their state of motion. In the absence of an unbalanced force, an object in motion will maintain this state of motion.

http://teachertech.rice.edu/Participants/louviere/Newton/law1.html

Law of ThermodynamicsAccording to Newton's second law...

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).

What does this mean? Everyone unconsciously knows the Second Law. Everyone knows that heavier objects require more force to move the same distance as lighter objects.

http://teachertech.rice.edu/Participants/louviere/Newton/law2.html

Law of ThermodynamicsAccording to Newton's third law...

For every action there is an equal and opposite re-action.

What does this mean?

This means that for every force there is a reaction force that is equal in size, but opposite in direction. That is to say that whenever an object pushes another object it gets pushed back in the opposite direction equally hard.

http://teachertech.rice.edu/Participants/louviere/Newton/law3.html

Newtonian Demonstrator• Instructions• Things You'll Need• Shoe box• Scissors• 5 identical beads• Hot glue• String

– 1Cut out rectangles from all four the sides of your shoebox. Leave about two inches of space around the top and sides so that you can attach your string to the Newton's Cradle.

– 2Measure out about 20 inches of string for each bead. Your Newton's Cradle will vary in size, depending on how large the shoe box is, so cut a piece of string that is long enough to allow you to adjust it before gluing it to the box.

– 3Thread a piece of string through each bead; loop the string back through so that the bead is held firmly in the middle of the string.

– 4Measure the length of the shoe box used for your Newton's Cradle and hang one bead across the width at the center, attaching the ends of the string to opposite sides of the top of the shoebox. Measure the width of each bead and mark that width two times on each side of the center bead's string ends.

– 5Attach the remaining beads to the Newton's Cradle so that all five beads sit in a straight line at the same height and are touching one another. Hot glue the strings to the box so that they will not shift from where you attached them.

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Read more: How to Build a Newton's Cradle | eHow.com http://www.ehow.com/how_5534301_build-newtons-cradle.html#ixzz1iy6XGxP1