Solving Physics Problems: Applying Principles and Formulas, Exams of Nursing

Download Solving Physics Problems: Applying Principles and Formulas and more Exams Nursing in PDF only on Docsity! Blueprint FL 5 CP If the average pitcher is releasing the ball from a height of 1.8 m above the ground, and the pitcher's mound is 0.2 m higher than the rest of the baseball field, at what height would the catcher need to hold his glove to catch the pitched ball? (Note: neglect air resistance, estimate the acceleration due to gravity as 10 m/s2, and assume the pitcher is only throwing the ball horizontally.) Average velocity = 30 m/s Distance b/t pitcher and mound = 18 m - correct answer ✔✔0.2 m ball's flight time is: (18 m) / (30 m/s) = (18/30) s = 3/5 s = 0.6 s The ball is released from a position 2 m off the ground (0.2 m from the pitcher's mound and 1.8 m from the pitcher). To calculate the distance the ball falls during 0.6 s, we can use the equation d = v0t + 1/2at2: d = (0 m/s)(0.6 s) + 1/2(10 m/s2)(0.6 s)2 d = 1/2(10)(0.36) = 1/2(3.6) = 1.8 The ball has fallen 1.8 m from an initial height of 2.0 m. Thus, the catcher must hold his glove 0.2 m above the ground to catch the pitch. How do you calculate the overall efficiency of a kinetic chain? - correct answer ✔✔multiply efficiency at each step How do you calculate total energy generated if you have an efficiency of 0.5 and a kinetic output of 65 J? - correct answer ✔✔Divide 65/0.5 -> 135 Entropy vs enthalpy - correct answer ✔✔enthalpy = heat energy in a system (∆H) -favorable = reaction LOWERS enthalpy b/c this means more stability entropy = energy in a closed system that is unavailable to do work / degree of randomness and disorder (∆S) -2nd law of thermodynamics -> every energy transfer that takes place will increase the entropy of the universe and reduce the amount of usable energy available to do work What is Hess's law - correct answer ✔✔The total enthalpy change of a reaction is independent of the route taken. ΔHrxn = Σ∆Hproducts - ΣΔHreactants A scientist uses an ultrasound device mounted to a vehicle to measure fluid flow underground. The device makes use of the Doppler effect to track fluid movement in the water table. Which of the following scenarios is most likely to produce a readable Doppler shift? I. The fluid is flowing at a velocity twice that of the sound-emitting device, in the same direction as the device is moving. II. The fluid is flowing at the same velocity and in the same direction as the sound-emitting device is moving. III. The fluid is not moving at all. - correct answer ✔✔I only The Doppler effect is used to analyze moving objects or fluids. A Doppler shift will be registered only if the fluid is moving relative to the source of the sound (the device). More specifically, at least some component of the fluid's velocity must exist in the same directional plane as the wave's velocity (otherwise, the device will register the fluid as not moving at all), and this component must be different from the velocity of the sound source. When the fluid travels with a different velocity than the sound source and in the same directional plane, it will produce a readable Doppler shift (I). Set equal to known Ksp 3.2 x 10^-14 = 4x^3 x = 2 x 10^-5 IR spectrum of O-H - correct answer ✔✔2500-3300 cm^-1 IR spectrum of C=O - correct answer ✔✔1650-1750 cm^-1 IR spectrum of C≡C - correct answer ✔✔2100-2260 cm^-1 IR spectrum of C-O - correct answer ✔✔1000-1320 cm^-1 Explain the type of shifts shielding and deshielding will cause in NMR - correct answer ✔✔shielding = upstream deshielding = downstream Geometric isomers - correct answer ✔✔-type of stereoisomer -have the same covalent arrangements but differ in spatial arrangements -ex = cis vs trans Constitutional isomers - correct answer ✔✔-same molecular formula, different connectivity -NOT a stereoisomer What are the strong acids - correct answer ✔✔HCl, HBr, HI, HNO3, H2SO4, HClO4 Why is HF not a strong acid? - correct answer ✔✔The reason HF is not a strong acid and HCl is a strong acid is a matter of structure. Looking at the conjugate bases, F- is far less stable than is Cl- due to its smaller size. When a smaller molecule has to bear a full formal charge it experiences a greater charge density and therefore more instability. A larger atom such as chlorine can spread out this charge over a greater area. Which of the following acids is expected to generate the strongest hydrogen bonding? A. HBr B. HCl C. HF D. HI - correct answer ✔✔HF Hydrogen bonding is a unique type of intermolecular force that occurs when H is bonded to very electronegative elements like F, O or N. Fluorine is the most electronegative element on the periodic table. Of the answer choices, only hydrogen fluoride is capable of hydrogen bonding. What molecules participate in hydrogen bonding - correct answer ✔✔F, O or N Hydrogen bonding occurs only in molecules where hydrogen is covalently bonded to one of three elements: fluorine, oxygen, or nitrogen Sublimation vs deposition - correct answer ✔✔-sublimation (solid to a gas) -deposition (gas to solid) Alpha particles have what charge - correct answer ✔✔+2 Amides act as ____________ (weak/strong + acid/base) - correct answer ✔✔weak base Ten moles of the monoprotic, weakly acidic medication aspirin were added to water to make one liter of solution. If the pH of the resulting solution was 5.9, what is the approximate Kb for the non-diffusible form of aspirin? - correct answer ✔✔0.1 Since we are given pH in the question stem, we will not be able to find Kb immediately. Instead, we need to calculate Ka and solve for Kb from that value. The Ka for the dissociation of a generic acid HA can be written as Ka = [H+][A-]/[HA], where all concentrations are measured at equilibrium. In the solution of aspirin described, the initial concentration of drug is 10 M. Since only a small amount of this weak acid will dissociate, this value is a good approximation for our final equilibrium [HA]. Next, we must find the proton concentration. Remember, [H+] = 10-pH. Here, the pH of the solution is 5.9, so [H+] = 10-5.9 M ~ 10-6 M. Since each HA molecule dissociates into equal parts [H+] and [A-], our value for [A-] must be 10-6 M as well. Returning to the Ka expression, Ka = [(10-6 M )(10-6 M)] / (10 - 10- 6 M). Remember, we can estimate that [HA] = 10 M, even though its true final value is 10 M - 10-6 M! [(10-6 M )( 10-6 M)] / (10 M) = 10-12 M / 10 M = 10-13 M In water at 25°C, Ka•Kb = 10-14. Given this, Kb = 10-14/Ka = 10 -14/10-13 = 10-1 = 0.1. Ka*Kb = - correct answer ✔✔Kw = 10^-14 How can you calculate [H+] and [A-] with pH - correct answer ✔✔[H+] = 10^-pH and [H+] = [A-] b/c HA dissociates into equal parts Earth is what type of system? - correct answer ✔✔closed What does a positive latent heat indicate - correct answer ✔✔indicates a phase change that is releasing energy -> either freezing, condensation, or deposition What does a negative latent heat indicate - correct answer ✔✔indicates a phase change that is consuming energy -> either melting, evaporation or sublimation