Assistance forSenior Success Using the Science Formula Page And Calculator Help
The Formula Chart for Science • On the science chart, the meanings of the letters in the formulas are given to you. • You must know the measurement units to know what numbers fit to which letter. • The box at the bottom provides some help . . . Let’s look.
When you don’t know – look! • Very important information is here. • Example: Newton which is the unit of Force is found by multiplying kg (mass) times m/s2 which is the unit for acceleration.
Example: What is the net force exerted on a 90.0 kg race-car driver while the race car is accelerating from 0 to 44.7 m/s in 4.50 s? F 9.8 N G 20 N H 201 N J 894 N We see kg, but not m/s2, so we have to calculate acceleration first . . Acceleration = Vf – Vi time A = 44.7 – 0 = 9.9 m/s2 4.5 So F = 90.0kg x 9.9 m/s2 =893.9 N
Science questions some times give more information than is needed. • Match units to formulas on the formula page. • Time should be in seconds in all formulas. • Mass must be in Kilograms for Force, Momentum, Work and Power. • Work and energy must be in Joules or Newton-meters. • This can be overwhelming if you try to wait until the day before to learn them. Try flash cards with units and what they measure.
XXXXXXXXXXXX A person pushes a large box across a level floor by applying a horizontal force of 200 N. If the person pushes the box a distance of 5 meters in 10 seconds, how much work does the person do on the box? A 2000 joules B 1000 joules C 400 joules D 100 joules • In problems with numbers; • find the question word, • look up the formula on the formula page, • Cross out information you do not need • put the numbers in the CALCULATOR in order. Work = force x distance No mention of time! or 200N x 5 m = 1000 joules
Let’s look at some related formulas . . . • The bottom equation says Speed, but uses v in the equation. • According to the top formula, v means velocity. • Velocity is more accurate since it is speed in one direction. • On TAKS these words are used interchangeably.
Momentum = mv so . . . 3 Which bike rider has the greatest momentum? A A 40 kg person riding at 45 km/h B A 50 kg person riding at 35 km/h C A 60 kg person riding at 25 km/h D A 70 kg person riding at 15 km/h 1800 1750 1500 1050 Just like on the Math test, plug in each answer and see which one works (it is the largest). . .
Most important . . . Do not guess, look and calculate!!
What good is the Periodic Table? There is a table provided for your use during the TAKS test, what can it do to help you?
What is an element? • Basically, if it is listed anywhere on the periodic table (of the elements) it is an element. • If it is on the left side it is a metal element, if it is on the right side it is a NONmetal element. (Hydrogen is the ONLY nonmetal to the left of the stairstep line.) • Let’s look . . .
Where are the metal elements? Left of the Stair-step line!
Where are the nonmetals? To the Right of the stair step line, and Hydrogen!
Where are the metalloids? • Along the stair step line. • These elements have properties of both metals and nonmetals.
The center elements on the table are called the transition metals. Many of them have more than 1 way they will give away electrons, so they change, or transition, ion charges. The charge these metals use are given by a roman numeral in the name. (Iron (II) chloride)
The Rare Earth Metals are radioactive and form the bottom 2 rows, also called the Lanthanide and Actinide Series.
So, I can tell if it’s a metal or not, what else? • Each column on the table is a group or family of elements that have similar chemical properties. • They form the same types of compounds, in the same ratio. • They have the SAME NUMBER OF OUTER SHELL (valence) electrons. • Lets look . . .
Group # 18 is the family called Noble Gases – each one has 8 outer shell electrons (full shell) so they don’t form compounds.
Group #1 is called the Alkalai metals, they have 1 valence electron, and will form +1 ions. The are Alkalai because they form the strongest (highest pH) bases.
Group #2 is called the Alkalai Earth Metals and they have 2 valence electrons, which they will give away to form +2 ions.
Group #17 are the Halogens, they all have 7 electrons in their valence shell, and want to have 1 more when they form compounds. They all become -1 ions when they can.
For each group, they form compounds the same way, for example. . . • Beryllium forms a compound with Cl in the ratio of 1:2 or BeCl2 • Since Mg and Ca are in the same family or group, they will form the same type of compounds in the same ratio. • MgCl2 and CaCl2 • This is what is meant when they have “similar chemical properties”
Each square also tells us information about each element. • The 1 or 2 letters that represent the element are its symbol. • The number at the top of the square is the atomic number. • The numbers at the bottom of the square is the average atomic mass.
What do the numbers mean? This is the atomic number. It is the number of protons in a single atom of this element. By the way, its also # of electrons. 11 Na The symbol for this element. This is the atomic mass, it is the number of protons + neutrons, or the mass of the nucleus of an atom. 22.990 sodium This is the name of the element.
Use the table, it will help you answer at least 5 questions! That may be the difference you need to pass!!
Now, let’s write some formulas and names • Roll one of each color, the positive ion is written first. • Use the charge as the subscript to the opposite ion, but remove the + or --. • If the ion is a group, DO NOT CHANGE THE GROUP, put it in ( ) with the number as a subscript outside. • To name it, write the name of the + ion, then name the – ion, or if it is an element, change the ending to –ide. Don’t forget the Roman Numeral for transition metals.
Law of Conservation of Mass • Matter can not be created or destroyed. • This means if it is on one side of an equation, it must be on the other, and there must be the same number of atoms of that element.
Thanks for coming . . . • Next week: • Monday – Math in Room 593 • Tuesday – Using formula charts and calculators with Test Taking Tips in the Teaching Theater • Wednesday – Science help here in Room 150
Objective 5 Review Quick Physics and Energy
Physics is about Energy and Motion • How and why do things move? • Do planets move the same way as a ball that is thrown? • These are the types of questions physics tries to answer.
Quick physics • Speed or Velocity = Distance / Time • Acceleration = Vfinal – Vstart / time to change • Work (joules) = Force (Newton) x distance (meters) • Power (watts) = Work / time
0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 3 3 3 3 3 3 3 3 4 4 4 4 4 4 4 4 5 5 5 5 5 5 5 5 6 6 6 6 6 6 6 6 7 7 7 7 7 7 7 7 8 8 8 8 8 8 8 8 9 9 9 9 9 9 9 9 Distance / Time = Speed so 20m / 40s = .5 m/s or . . . . 5 • A toy car moves 20 m in 40 seconds. What is the speed of this car?
0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 3 3 3 3 3 3 3 3 4 4 4 4 4 4 4 4 5 5 5 5 5 5 5 5 6 6 6 6 6 6 6 6 7 7 7 7 7 7 7 7 8 8 8 8 8 8 8 8 9 9 9 9 9 9 9 9 Acceleration = Vf – Vi / Change in time so . . . 35m/s – 15m/s / 10 s = 2 m/s/s 5 • An object is moving at 15 m/s and after 10 seconds the object is moving at 35 m/s. What is the acceleration of the object?
A young man is standing in line at the grocery store holding a 12-pack of Coke weighing 50 N in his arms which are 1.5 meters off the ground. How much work is he doing? • 0 Joules • 6.25 Joules • 33.3 Joules • 75 Joules Work = force x distance = 50N x 1.5m Or = 75 Joules _
Power = Work/time but nothing here is in Joules Work = force x distance so . . . Power = 550N x 5m / 3.5 s = 9625 watts • Lakiesha weighs 550 Newtons runs to the top of the 5 m tall staircase in 3.5 seconds. How much power is Lakiesha demonstrating? • 385 Watts • 559 Watts • 786 Watts • 9625 Watts
Sir Isaac Newton and the 3 Laws of Motion • Considered one of the foremost physicists, • Described the motion of all things in a gravity and friction free system. • For each of the next slides, write at least 3 examples of each law in action. . .
Newton’s FIRST Law • Law of Inertia • An object at rest or in motion remains that way until acted upon by an unbalanced force.
Newton’s SECOND Law • Force = Mass x Acceleration • The greater the force on an object in a single direction the greater the acceleration in that direction will be.
Newton’s THIRD Law • Law of Action/Reaction • For every action force there is an equal and opposite reaction force. • Motion is the result of unbalanced forces on the same object.
Lever 1st Class with the fulcrum in the middle 2nd Class with the resistance in the middle 3rd Class with the effort in the middle To determine the lever classes three, what is in the middle spells FRE. Pulley, Wheel and Axle, Inclined Plane, Wedge and Screw There are 6 simple machines
Mechanical Advantage and Efficiency, Why Not 100% ? • Mechanical advantage is how much your force is multiplied by the machine • Efficiency is • Actual MA/Ideal MA • Never 100% due to FRICTION • Almost all energy that is not converted into work is converted into heat.
Transverse Waves vibrate 90o from the direction of travel. All electromagnetic waves are in this group. Visible light and the color spectrum are all transverse waves. Water ripple waves and microwaves are also of this type Compression Waves move in the same direction as their vibration. Sound waves, caused by a disturbance, carried through a medium are of this type. Some types of earthquakes are also compression waves. Waves
The Electromagnetic Spectrum Shortest to Longest Gamma X rays Ultraviolet Visible Infrared Micro- TV/Radio Radiation Light Light Radiaion waves Waves Remember: Long – Low – Slow: Long wavelength is a low frequency and slow velocity.
C A D B • Which of the following waves would have the highest pitch and lowest volume?
Speed = frequency x wavelength • All radiant energy travels at the same speed. • 3 x 108 meters/sec • This is the speed of light through space. • Radio waves and nuclear energy waves travel at the same velocity.
Speed = frequency x wavelength so 343 m/s = 512.5 Hz x wavelength • A sound wave is traveling at 343 m/s and has a frequency of 512.5 Hz, what is its wavelength? • 0.67 m • 1.5 m • 169.5 m • 855.5 m
Light Spectrum • Visible light is a small part of the electromagnetic spectrum. • Violet is the shortest wavelength, red the longest of visible light. • As wavelength increases, frequency? Answer: Decreases!
Waves move, so there can be interference . . . • When something is an interference, it changes the path of movement. • Constructive means it adds to the wave’s energy or amplitude • Destructive cancels or decreases the wave’s amplitude
After passing through the barrier, it will spread back out and continue on the same path. The diagram shows waves approaching a barrier. Which pattern will be formed after the waves pass through the opening in the barrier?
Ohm’s LawVoltage = Current x Resistance Standard American Current – 110V @ 15 or 20 Amps Power, measured in Watts is P = VI