IES Auringis. Jaén. José Cayetano Bautista Expósito 4º ESO. Physics and Chemistry. Unit 4 Read the directions for each task, then go to each website and find the information. Write the answers on a paper with your name on it. Task 1 : Who was Isaac Newton? What important contributions did he make to science? http://www.windows.ucar.edu/tour/link=/people/enlightenment/newton.html Task 2: What was Isaac Newton's childhood like? http://www.pbs.org/wnet/hawking/cosmostar/html/cstars_newt.html Task 3: Look at a picture of Isaac Newton. Write 1 or 2 sentences that describe what he looks like. http://www.google.com Task 4: What is Newton's 1st law? Describe the example of Newton's 1st Law from the webpage. Has this ever happened to you? What did Newton call his first law? http://www.schools.utah.gov/curr/science/sciber00/8th/forces/sciber/newtons.htm Task 5: Newton's 2nd law is F = MA. Write the formula in words. Why does a speeding bullet and a moving train have so much force? http://www.schools.utah.gov/curr/science/sciber00/8th/forces/sciber/newton2.htm Task 6: What is Newton's 3rd law? What example was described on this webpage? http://www.schools.utah.gov/curr/science/sciber00/8th/forces/sciber/newton3.htm Task 7 : What is friction? What are the three types of friction? http://www.schools.utah.gov/curr/science/sciber00/8th/forces/sciber/forcmot.htm Task 8: Which velocity will reach a car, with a weight of 950 Kg, that goes at 55 km/h if the engine force of 2500 N pushes it forward during 2 minutes and there is a fluid friction force caused by air of 100 N and a rolling friction force of 250 N caused by the wheels? If the engine stops suddenly at that speed, and we consider that the friction forces remain with the same values, how long does the car take to stop?
IES Auringis. Jaén. José Cayetano Bautista Expósito 4º ESO. Physics and Chemistry. Unit 3. <ul>Standard Atmospheric Pressure (atm) is used as a reference for gas densities and volumes. The Standard Atmospheric Pressure is defined at sea-level at 273oK (0oC) and is 1.01325 bar or 101325 Pa (absolute). In imperial units the Standard Atmospheric Pressure is 14.696 psi. 1 atm = 1.01325 bar = 101.3 kPa = 14.696 psi (lbf/in2)= 760 mmHg =760 torr = 1013 mbar Pressure Units: S ince 1 Pa is a small pressure unit, the unit hectoPascal (hPa) is widely used, especially in meteorology. The unit kiloPascal (kPa) is commonly used design of technical applications like piping systems and similar. 1 hectoPascal = 100 Pascal = 1 millibar 1 kiloPascal = 1000 Pascal Some Alternative Units of Pressure 1 bar - 100,000 Pa 1 millibar - 100 Pa 1 atmosphere - 101,325 Pa A torr (torr) is named after Torricelli and is the pressure produced by a column of mercury 1 mm high - equals to 1 / 760th of an atmosphere. 1 atm = 760 torr = 14.696 psi </ul>
IES Auringis. Jaén. José Cayetano Bautista Expósito 4º ESO. Physics and Chemistry. Unit 3. <ul>Aneroid barometers. Most barometers we encounter use a mechanical mechanism of some sort rather than columns of liquid to sense atmospheric pressure. These are called aneroid barometers. The word "aneroid" somehow means "without liquid." A typical aneroid barometer utilizes a bellows made of thin metal that expands or contracts as the air pressure changes. The movement of the bellows is communicated to the indicator needle by an intricate linkage that also provides for adjustment and calibration. In fact, the altimeters on our planes are aneroid barometers with a few modifications. Digital barometers change pressure into an analog electrical signal by the physical deformation of strain gages. Pressure produces a deflection of the diaphragm which introduces strain to the gages. The strain will produce an electrical resistance change proportional to the pressure. This electrical signal is treated by electronics to present the pressure in a display </ul>
IES Auringis. Jaén. José Cayetano Bautista Expósito 4º ESO. Physics and Chemistry. Unit 3. <ul>Variation of air pressure with altitude Just as a diver experiences a decrease in pressure as he or she rises toward the surface, we experience a similar decrease in pressure as we climb to higher altitudes in our planes, or climb to the top of a mountain, or go from the basement to upstairs at home. Atmospheric pressure varies somewhat on a day-to-day basis. When the readings are taken over a long period of time in many different locations and then averaged, it is found that the average pressure at sea level is very nearly 760 millimetres (mm) of mercury. This value has been taken (somewhat arbitrarily) as the "standard value." A standard atmosphere calculator with graphs and other information can be found at http://www.digitaldutch.com/atmoscalc/ The calculator lets you insert an altitude, and it then gives you the standard pressure, temperature, density, and speed of sound at that altitude. Activities 1.- Find the altitude of Jaén. Go to http://www.digitaldutch.com/atmoscalc/ and introduce the found altitude to get the pressure in Jaén. Do the same with the altitude of Mulhacen and Himalayas and compare the results. 2.- Find information about Otto von Guericke. How did he demonstrate the power of a vacuum? </ul>