# si unit exercises

(b) Making the same assumption, how many cells are there in a human? The following lengths are given using metric prefixes on the base SI unit of length: the meter. In what follows, assume A is area, V is volume, and all other variables are lengths. The LibreTexts libraries are Powered by MindTouch® and are supported by the Department of Education Open Textbook Pilot Project, the UC Davis Office of the Provost, the UC Davis Library, the California State University Affordable Learning Solutions Program, and Merlot. How many Earths would it take to equal the mass of the Sun? How many moons would it take to equal the mass of Earth? Worksheet 1 Worksheet 2 Worksheet 3 Worksheet 4 Square Meters to Square Centimeters. How many Moon atmospheres would it take to equal the mass of Earth’s atmosphere? (b) What is the difference between a base quantity and a derived quantity? Will the criteria necessarily be as strict for an expected result as for an unexpected result? For example, 47 Ts would be rewritten as 4.7 × 10, The following times are given in seconds. Mount Everest, at 29,028 ft, is the tallest mountain on Earth. Using dimensional analysis, he was then able to deduce the amount of energy released in the explosion, which was a closely guarded secret at the time. More precisely, show that (a) 1.0 m/s = 3.6 km/h and (b) 1.0 m/s = 2.2 mi/h. The last few pages have covered a lot of information about SI units and some related topics. A fortnight is 2 weeks. (a) A person’s blood pressure is measured to be 120 ± 2 mm Hg. Units of measurement are important for of all physical quantity. Finally, scientists came up with a unit of measurement that can replace all other existing ways we measure objects. Metric/SI Unit Conversion: Area 3. Determine the number of significant figures in the following measurements: (a) 0.0009, (b) 15,450.0, (c) 6×103 , (d) 87.990, and (e) 30.42. This system of measurement is called the . (a) Estimate the density of the Moon. Assume the average mass of an atom in the bacterium is 10 times the mass of a proton. (b) If the uncertainty in each number is 1, what is the percent uncertainty in each? Roughly how many times longer than the mean life of an extremely unstable atomic nucleus is the lifetime of a human? Rewrite them in scientific notation in terms of the SI base unit of mass: the kilogram. Rewrite them in scientific notation without the prefix. Tectonic plates are large segments of Earth’s crust that move slowly. For example, the area of a square having a side of 2 cm is 2 cm × 2 cm, or 4 cm 2 (read as “four centimeters squared” or “four square centimeters”). intensity It is defined by taking the fixed numerical value of the luminous efficacy of (a) What is this in meters per second? International System of Units (SI). Based on the definitions of force and area, the, Newton's law of gravitational force states F = (G m. Helen of Troy had "a face that could launch a thousand ships." Each prefix multiplies the base unit by a certain power of ten (10, 100, 1000, and so on). (b) Find the uncertainty in this volume. Answer the following to the best of your ability. A new page will appear showing your correct and incorrect responses. The first atomic bomb was detonated on July 16, 1945, at the Trinity test site about 200 mi south of Los Alamos. Also explore over 10 similar quizzes in this category. Using keen physical insight developed from years of experience, Taylor decided the radius r of the fireball should depend only on time since the explosion, t, the density of the air, ρ, and the energy of the initial explosion, E. Thus, he made the educated guess that $$r = kE^{a} \rho^{b} t^{c}$$ for some dimensionless constant k and some unknown exponents a, b, and c. Given that [E] = ML, By analyzing data from high-energy conventional explosives, Taylor found the formula he derived seemed to be valid as long as the constant k had the value 1.03. (c) Which is a more meaningful way to express the accuracy of these two numbers: significant figures or percent uncertainties? Because of this, Taylor did not publish his results until 1950. What is its area in square feet? For example, 40 Mg would be written as 4 × 10. What is the freezing point in (a) K; (b) °F? The speed limit on some interstate highways is roughly 100 km/h. This section covers unit conversion worksheets for converting metric/SI volumes (liter base units) between other metric units, for example milliliters to liters, centiliters to liters, etc. For the remaining questions, you need to use Figure 1.4 to obtain the necessary orders of magnitude of lengths, masses, and times. What is the density of water in pound-mass per cubic foot? Have questions or comments? The SI or International System of Units (from the French Système international d'unités) as we know it today was developed in 1960 in order to establish an internationally agreed set of quantity measurement standards. It comprises a coherent system of units of measurement starting with seven base units, which are the second (the unit of time with the … Privacy Policy| For many patients, this leads to less stress when per-forming everyday tasks. How long is the field in meters? The Metric System. (b) Assuming the same percent uncertainty, what is the uncertainty in a blood pressure measurement of 80 mm Hg? Suppose quantity s is a length and quantity t is a time. Just like all objects are addressed by some name, physical quantities are known by the units of measurement. Consider the equation y = mt +b, where the dimension of y is length and the dimension of t is time, and m and b are constants. (b) What is its speed in kilometers per million years? This system comprises seven base quantities and 16 prefixes that designate amount. Length (millimeters to meters and similar), volume (milliliters to liters and similar) and mass (milligrams to grams and similar.) How much is left after 308 mL is removed? (b) The force F on an object is equal to its mass m multiplied by its acceleration a. What should you do after obtaining a numerical answer when solving a problem? Take the Quiz and improve your overall Physics. SI system – properties • based on a set of 7 base units • by convention these are assumed to be independent • other units are formed as products of powers from base units (derived units) • some derived units have special names like Newton • system is coherent i.e. Copyright © Oxford University Press, .All Rights Reserved. In order to best absorb this information and test your understanding, we recommend that you try some of the following exercises on this topic. The SI system of units (often referred to as the metric system) is the official system for measurements in nearly all countries of the world, but not in the U.S. As our society and economy become more global in scope, it is increasingly important to fully comprehend both the English and the SI systems of units and to accurately an… Metric measurement is based on the number ten and … tall? When nonmetric units were used in the United Kingdom, a unit of mass called the pound-mass (lbm) was used, where 1 lbm = 0.4539 kg. Convert a speed of one furlong per fortnight to millimeters per second. American football is played on a 100-yd-long field, excluding the end zones. Derived SI Units. (a) You want to tabulate the mean distance from the Sun for each planet in the solar system. The radian is a special name for an SI derived unit. What is the area of a circle 3.102 cm in diameter? Area is the amount of space taken up by a two dimensional surface. Answer: Option C. Roughly how many heartbeats are there in a lifetime? Try this amazing SI Units Quiz: Knowledge Test! Note 1 km = 0.6214 mi. Pressure is defined: P = Force/Area. The SI unit of mass is the: Kilogram Gram Milligram Pound The SI unit for the amount of material present is the: Kilogram Mole Bushel Dozen The SI unit of volume is the: Liter Gallon MilliLiter m 3 (cubic meter) Pressure is defined: P = Force/Area. What determines the validity of a theory? Legal. Units are extremely important in the study of science. For each of the following scenarios, refer to Figure 1.4 and Table 1.2 to determine which metric prefix on the meter is most appropriate for each of the following scenarios. The average density of the Sun is on the order 10. Roughly how many solar systems would it take to tile the disk of the Milky Way? For more information contact us at info@libretexts.org or check out our status page at https://status.libretexts.org. (c) In 2.000 years? A milliHelen is a face that could launch: 1 The symbol representing the metric prefix "milli" is, 1 The symbol representing the metric prefix "mega" is, 1 The symbol representing the metric prefix "micro" is. What is the percent uncertainty in this measurement? (b) Based on that percent uncertainty, what mass in pound-mass has an uncertainty of 1 kg when converted to kilograms? (b) What is the relationship between the accuracy and the discrepancy of a measurement? Put the quantities below into SI units to perform the requested calculation (click on the green letters for the solutions). How many beats does he or she have in 2.0 years? Use metric prefixes to rewrite them so the numerical value is bigger than one but less than 1000. Scientists use a refined version called the International System of Units (abbreviated SI).In biology, you will often find a need to describe measurements of length, volume, mass, time, temperature or amount of substance. Scientists all over the world use the same system of units so they can communicate information clearly. Without them, a number is just a number without any meaning. What is the total weight of the bags? (c) What is the difference between a base quantity and a base unit? The following times are given using metric prefixes on the base SI unit of time: the second. 1.836x10 3: 5.47x10-4: 1.84x10 3: 1 4 Units outside the SI 123 4.1 Non-SI units accepted for use with the SI, and units based on fundamental constants 123 4.2 Other non-SI units not recommended for use 129 5 Writing unit symbols and names, and expressing the values of quantities 130 5.1 Unit symbols 130 5.2 Unit … Samuel J. Ling (Truman State University), Jeff Sanny (Loyola Marymount University), and Bill Moebs with many contributing authors. Questions left blank are not counted against you. What is the volume of a 12 fl-oz can of soda pop in cubic meters? Calculate the approximate number of atoms in a bacterium. What are the dimensions of (a) s, (b) r, and (c) $$\Theta$$? Can the validity of a model be limited or must it be universally valid? Virtually every other country in the world now uses SI units as the standard; the metric … A can contains 375 mL of soda. How many protons would it take to equal the mass of the Sun? A floating-point operation is a single arithmetic operation such as addition, subtraction, multiplication, or division. Exceptions to the latter include the US … A light-nanosecond is the distance light travels in 1 ns. In 1947, the U.S. government declassified a film reel of the explosion. The arc length formula says the length s of arc subtended by angle $$\Theta$$ in a circle of radius r is given by the equation s = r$$\Theta$$. (c) Given that the Moon subtends at an angle of about half a degree in the sky, estimate its distance from Earth. An infant’s pulse rate is measured to be 130 ± 5 beats/ min. Stretching the muscles around the SI joint consistently can help loosen tight muscles, as well as improve range of motion. Practice your math skills. What is the uncertainty in your mass (in kilograms)? (b) How many miles per hour is this? A commonly used unit of mass in the English system is the pound-mass, abbreviated lbm, where 1 lbm = 0.454 kg. For example, 4.2 Pm would be rewritten as 4.2 × 10 15 m. 89 Tm; 89 pm; 711 mm; 0.45 µm. Calculate the voltage across a (b) What is the dimension of the quantity a? A good-quality measuring tape can be off by 0.50 cm over a distance of 20 m. What is its percent uncertainty? Some have described physics as a “search for simplicity.” Explain why this might be an appropriate description. For example, 7.9 × 10, The following masses are written using metric prefixes on the gram. (a) The prefix kilo-means 1000 basic units; thus, 1 km = 1000 m. The two unit factors are (b) The prefix deci - means 0.1 basic unit; thus, 1 g = 10 dg. How does this compare with the required validity of a theory or a law? The mentioned "$\mathrm{rads/s}$" is not a correct SI unit symbol. What are the dimensions of (c) $$\int$$vdt, (d) $$\int$$adt, and (e) da/dt? Metric SI Volume This is how the SI unit of measurement came about. The international system of units, called SI units, solves this problem by using prefixes. SI Units 341 International System of Units (SI Units) Analyte Gravimetric Conversion International Unit Factor Unit Cholesterol, Total mg/dL 0.0259 mmol/L Chromogranin A ng/mL 1.0 μg/L Collagen Cross-Linked nmol BCE/ 1.0 nmol BCE/ N-Telopeptide (NTx) mmol creat mmol creat Collagen Type 1 C-Telopeptide (CTx) pg/mL 1.0 ng/L (Note there are on the order of 10. (Assume that 1 m = 3.281 ft.). The Système international d’unités (SI system) is a standard that simplifies international scientific communication. (a) Suppose that a person has an average heart rate of 72.0 beats/min. Suppose your bathroom scale reads your mass as 65 kg with a 3% uncertainty. (a) What is its speed in kilometers per hour? Ethylene glycol, the major ingredient in antifreeze, freezes at -11.5°C. Derived units are combinations of SI base units. Quiz type: One-step conversions (convert to & from base units, easier) Two-step conversions (convert to & from units with prefixes, harder) It has been adopted throughout the world for use in science and technology, and by most countries for day-to-day use. Use the orders of magnitude you found in the previous problem to answer the following questions to within an order of magnitude. Table 2.1 SI Base Quantities and Units* international usage in scientific, technical, industrial ... Luminous candela cd The candela, symbol cd, is the SI unit of luminous intensity in given direction. Rewrite them in scientific notation without the prefix. The following lengths are given in meters. This is a collection of 10 chemistry test questions with answers dealing with unit … Identify some advantages of metric units. This keeps the numbers you're working with manageable, while quickly identifying the relationship between very large and very small units. Exercises Additional exercises 2020-21. (a) A woman has two bags weighing 13.5 lb and one bag with a weight of 10.2 lb. The metric system is an internationally agreed-upon measurement system based on decimals or powers of 10. (a) What is the dimension of v? (Note that the Wikipedia page on Coriolis frequency also shows wrong units symbols for the hour "$\mathrm{hr}$" and minute "$\mathrm{m}$ ".) A student is trying to remember some formulas from geometry. How many radians are in 1°? What is the difference between a base unit and a derived unit? A marathon runner completes a 42.188-km course in 2 h, 30 min, and 12 s. There is an uncertainty of 25 m in the distance traveled and an uncertainty of 1 s in the elapsed time. The content of each of the exercises is listed below, so that you may jump to any ones you wish. A long time ago, people from different countries had different ways of measuring things, which made it harder for them to trade. Feb 21, 2017 - Unit conversion worksheets for the SI system, or metric system. What is this measurement in kilometers per hour? SI Units - Section 1. The average distance between Earth and the Sun is 1.5 × 10, The density of nuclear matter is about 10. Missed the LibreFest? Luminosity candle cd 1979, 16th CGPM: The candle (or candela) is the luminous intensity, in a given direction, of a source that emits monochromatic radiation of frequency 540.1012 hertz and that has a (a) By what amount is the gas decreased in volume in cubic centimeters? Measurements: Different parts of the world use different units of measurement. For example, 7 × 10−4 kg could be written as 70 cg or 700 mg. This problem challenges you to recreate this famous calculation. For historical reasons, the name "kilogram" for the SI base unit of mass contains the name "kilo," the SI prefix for 10 3.Thus, because compound prefixes are unacceptable, symbols for decimal multiples and submultiples of the unit of mass are formed by attaching SI … (c) You want to list the diameters of all the elements on the periodic table. 1. There are two major systems of units used in the world: SI units (also known as the metric system) and English units (also known as the customary or imperial system). For example a piece of wire length is 3 meters. Approximately how many generations have passed since the year 0 AD? About how many floating-point operations can a supercomputer perform each year? (b) How long would it take a supercomputer to perform that many floating-point operations? What information do you need to choose which equation or equations to use to solve a problem? Strictly speaking, weight is the force (F) associated with a given mass (m) as it is accelerated (a) by gravity: F = m × a The English System unit of mass is the slug, which when multiplied by the acceleration of gravity (32 ft/sec 2) gives the weight in pounds. Roughly how many floating-point operations can a supercomputer perform in a human lifetime? Unless otherwise noted, LibreTexts content is licensed by CC BY-NC-SA 3.0. A. degree fahrenheit B. degree centigrade C. degree kelvin D. degree absolute. Useful math exercises on length unit conversion. Calculate its volume and uncertainty in cubic centimeters. Consider the equation 4000/400 = 10.0. What are the dimensions and SI units of (a) s. (a) A car speedometer has a 5% uncertainty. The SI base units in Table 1.4 are used to derive the units of other quantities. Use metric prefixes to rewrite them so the numerical value is greater than one but less than 1000. (a) What is the relationship between the precision and the uncertainty of a measurement? (b) Calculate the percent uncertainty in the elapsed time. For example, 4.2 Pm would be rewritten as 4.2 × 10, The following lengths are given in meters. Convert 1 ft to light-nanoseconds. For example, 7.9 × 10, The following lengths are given using metric prefixes on the base SI unit of length: the meter. (Assume that 1 m = 3.281 ft.). Perform the following calculations and express your answer using the correct number of significant digits. For simple shapes like a rectangle, it is calculated by multiplying the length times the width of the shape. If two different theories describe experimental observations equally well, can one be said to be more valid than the other (assuming both use accepted rules of logic)? (b) Estimate the diameter of the Moon. (Assume that 1 m = 3.281 ft.), Soccer fields vary in size. Convert length units on Math-Exercises.com - Online collection of math exercises. This online quiz is intended to give you extra practice in converting SI units. (a) Calculate the number of cells in a hummingbird assuming the mass of an average cell is 10 times the mass of a bacterium. The SI derived units for these derived quantities are obtained from these equations and the seven SI base units. 104 Metric SI Unit Conversions Worksheets. The the correct special symbol for the radian is $\mathrm{rad}$. In this problem, you will see that 1 m/s is roughly 4 km/h or 2 mi/h, which is handy to use when developing your physical intuition. A car engine moves a piston with a circular cross-section of 7.500 ± 0.002 cm in diameter a distance of 3.250 ± 0.001 cm to compress the gas in the cylinder. Examples of such SI derived units are given in Table 2, where it should be noted that the symbol 1 for quantities of dimension 1 such as mass fraction is generally omitted. When you have completed every question that you desire, click the "MARK TEST" button after the last exercise. Answers: (a) 261.7 K; (b) 11.3°F Derived SI Units. State how many significant figures are proper in the results of the following calculations: (a) (106.7)(98.2) / (46.210)(1.01); (b) (18.7). The terms mass and weight are often used interchangebly in chemistry. Rewrite them in scientific notation without the prefix. (a) Calculate the percent uncertainty in the distance. (b) You want to compare the sizes of some common viruses to design a mechanical filter capable of blocking the pathogenic ones. SI Units. (d) You want to list the distances to all the stars that have now received any radio broadcasts sent from Earth 10 years ago. (a) Ohm’s law V = IR links the voltage V across a resistance R to the current I ﬂowing through it. Today it is very important to be able to understand measurements in both the English system of units and the SI (Systems International) system of units. Suppose one such plate has an average speed of 4.0 cm/yr. Certain criteria must be satisfied if a measurement or observation is to be believed.