Problem: Convert 25kg to ug. Problem: Convert 482mL to cl. Problem: How many micrograms are in a kilogram? Problem: How many ml are in 1 ounce? Problem: How many ml are in 1 tsp? Problem: A nerve impulse in the body can travel as fast as 400 feet/second. What is its speed in meters/min? Ch 1 (Part 2 - Measurement) Page29
Problem: Drug dosages are typically prescribed in units of milligrams of drug per kilogram of body weight. A new drug has a recommended dosage of 9.0 mg/kg. How many mg would a 130. lb woman have to take to obtain this dosage? Pathway: 130. lb? kg body weight? dosage 1.11 Temperature, Heat, & Energy Energy The capacity to Temperature The measure of the (energy of motion) of the particles. Simple definition: A measure of how hot or cold an object is. Temperature a measure of the heat energy. Commonly reported either in units of degrees Fahrenheit ( Celsius ( ), but the SI unit for temperature is the Kelvin ( ). (Note that we say only Kelvin, not degrees Kelvin. ) ) or degrees Ch 1 (Part 2 - Measurement) Page30
Fahrenheit Temperature Scale Defined by German scientist Daniel Gabriel Fahrenheit in late 1600s or early 1700s. Defined by a) freezing temperature of saturated salt solution (intended to be 0 F) and b) temperature of the human body (intended to be 100 F, turned out to be 98.6 F) Current markers are freezing point of water ( ) and boiling point of water ( ). There are between freezing and boiling. Currently in use primarily only in the United States Celsius Temperature Scale Suggested by Swedish astronomer Anders Celsius in the mid 1700s. Sometimes referred to as the Centigrade Temperature Scale. Defined by freezing temperature of water ( ) and boiling point of water ( ). There are between freezing and boiling. Ch 1 (Part 2 - Measurement) Page31
Kelvin Temperature Scale Both Fahrenheit and Celsius temperature scales require the use of numbers. However, there is a limit to how low temperature can go. This was discovered through hundreds of experiments. William Thompson (a.k.a. ) suggested in mid to late 1800s a scale that does not use negative numbers. The kelvin and the Celsius degree are the. Thus, a change in temperature of 1 o C is equal to a change of 1 K. The Celsius scale assigns a value of 0 o C to The Kelvin scale assigns a value of 0 K to absolute zero, which is equal to. Temperature Conversions To go from freezing to boiling water in Fahrenheit degrees, it takes 180 To go from freezing to boiling water in Celsius degrees, it takes 100 If we divide both by 20, a change in temperature of Conversion Factors is equal to a change of. 9 F = * C + 32 5 5 C = ( F 32 F) 9 K = C + 273.15 C = K 273.15 Ch 1 (Part 2 - Measurement) Page32
Problem: If it is 20 C outside, what is the temp. in F? 30 C is 20 C is 10 C is 0 C is Problem: If it is 75 F outside, what is the temp. in K? First convert to C. Then convert to K. Temperature sensitive Materials Thermochromic materials change as their temp changes. These can be incorporated into materials and used to monitor the temperature of the products or packages in which they are incorporated. Many medical facilities now routinely use temperature strips that change color to indicate body temperature. Ch 1 (Part 2 - Measurement) Page33
Energy and Heat Energy Two basic forms of Energy Kinetic Energy:. Potential Energy: Heat Heat is the amount of heat energy in an object. It is the of the moving particles that make up matter. Energy is represented in SI units by the unit, but the metric unit is still widely used. 1 cal = 4.184 J 1 cal = the heat required to raise gram of water by. A kilocalorie ( nutritionists, equals. ), called a large calorie (Cal) or food calorie by One calorie raises the temperature of 1 g of water by 1 C, but raises the temperature of 1 g of iron by 10 C. The amount of heat needed to raise the temperature of 1 g of a substance by 1 C is called its The high specific heat of water makes it hard to change our body temperature. Ch 1 (Part 2 - Measurement) Page34
Specific Heat (c) = heat. heat can be in calories or Joules mass x T mass is usually expressed in grams Problem: What is the specific heat of aluminum if it requires 4.35 Joules of energy to raise the temperature of 2.00g of aluminum 2.4 degrees C? Try this on your own calculator! Calculating Heat Gained or Lost Heat = mass x specific heat x temperature change Problem: How much heat is required to heat 1.00 quart of water from room temperature (22 C) to boiling? The specific heat of water is 1.00 cal/g C. 1 liter = 1.057 quarts 1.00 ml of water weights 1.00g First solve for the individual elements of the problem. We are given c = Be sure to use DA to help solve for the mass!!! T = Plug in the intermediate results and solve. Ch 1 (Part 2 - Measurement) Page35
How many dietary calories is this? This means that digesting one Oreo cookie (68 Cal) generates almost enough energy to boil a quart of water. Our bodies require enormous amounts of energy to keep them running!!!!! Problem: What is the final temperature if 350. Cal of heat is added to a 125g sample of iron at 18.0 C if it has a specific heat of 0.106 cal/g C? 1.12 Density and Specific Gravity Density Density is the ratio of the mass of an object to its volume. Mass Density = ------------ Volume Density is a characteristic property of a substance. It usually has units of g/cm 3 (solids) or g/ml (liquids). Density is stated at a given temperature. Density of Water = 1.00 g/ml at 4 degrees C. (It s maximum density.) Ch 1 (Part 2 - Measurement) Page36
Most substances when cooled, and when heated. Water first contracts when chilled, then expands when it freezes, (most dense(1.00 g/ml) at ) so ice floats on liquid water. Substances with lower densities will float on ones with higher densities. Problem: What is the density of 5.00 ml of serum if it has a mass of 5.23 grams? What would the mass of 1.00 liters of this serum be? Problem: Will a 10.0 lb bowling ball of standard diameter (8.50 ) float or sink in water at room temp. Water has a density of 0.998g/mL. (V=4/3πr 3 ) Mass = 10.0 lb x 453.6 g = 4536 g 1 lb Radius = d = 8.50 in = 4.25 in x 2.54 cm = 10.795 cm 2 2 1 in Volume = 4πr 3 = 4(3.14159)(10.795cm) 3 = 5269cm 3 3 3 Density = m = 4536g v 5269cm 3 = 0.8609 0.861g/cm 3 0.861g/mL It will float since < density of water! Ch 1 (Part 2 - Measurement) Page37
Measuring density of Solids - Measure the mass of the solid before submerging it in water to determine its volume. Mass = - Volume displacement is the volume of a solid calculated from the volume of water displaced when it is submerged. Volume = - To get the density, divide the mass by the volume. Problem: If you poured some blood plasma and some human fat into the same container and allowed them to separate, which one would be on the bottom? Ch 1 (Part 2 - Measurement) Page38
Specific Gravity Specific gravity is the density of a divided by the density of a reference substance (usually ) at the same temperature Density of Substance (g/ml) Specific Gravity = ---------------------------------------------------------------------- Density of Reference Substance (g/ml) At normal temperatures, the specific gravity of a substance is numerically its density, but has no The specific gravity of a liquid can be measured using an instrument called a. Hydrometers contain a weighted bulb at the end of a calibrated glass tube. The depth to which the hydrometer sinks in the fluid indicates the fluid's specific gravity. The lower the hydrometer sinks, the lower the specific gravity. Urinometers (a specialized hydrometer) are used to measure dissolved solids in urine. Urinometers can help identify. If you are dehydrated, the density of the urine will be than normal. A Galileo Thermometer is based on the variation in Ch 1 (Part 2 - Measurement) Page39
Obesity and Body Fat Obesity is defined by reference to the body mass index. Body Mass Index weight ( kg) BMI = = height m ( ) weight ( lb) height ( in) x 2 2 270 BMI of or above is considered overweight. BMI of or above is considered obese. By these standards, approximately 61% of the U.S. population is overweight. The lowest death risk from any cause, including cancer and heart attack was for BMI 22-24. By BMI of 29, the risk doubles! (McMurry 8 th Ed.) Practice Problem for Dimensional Analysis using BMI. Based on the BMI scale, is a 6 2 man who weighs 250. lb obese? Mass = Height = BMI = Ch 1 (Part 2 - Measurement) Page40
More Dimentional Analysis Practice Problem: How many km are in 5842.5 miles? Problem: If a normal blood level of HDL (high density lipoprotein, aka good cholesterol) should be >45 mg/dl and a total of 0.0015g of HDL was found in a 2.0mL sample of blood, is it within the normal range? 45 mg/dl means: Ch 1 (Part 2 - Measurement) Page41
Problem: Synthroid full replacement recommended dose = 1.7μg/kg/day. If pills are available in 0.100mg, 0.125mg, 0.137mg, 0.150mg, and 0.175mg, what should the doctor prescribe for a 175lb man to take? Doseage means: Problem: If morphine sulfate comes in a 240. ml bottle with a concentration of 20. mg/ml, how many doses are in the bottle if a patient receives 30. mg every 4 hours? Ch 1 (Part 2 - Measurement) Page42