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

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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) d = 1/2(10)(0.36) = 1/2(3.6) = 1. 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).

What is presbyopia and how is it corrected? - correct answer ✔✔-far-sightedness -image formed BEHIND retina -fixed with CONVERGING (convex) lens What is myopia and how is it corrected? - correct answer ✔✔-near-sightedness (what I have) -image formed IN FRONT of retina -fixed with DIVERGING (concave) lens Light inside the thin glass tube of a laproscopic surgical device strikes the edge of the glass tube and is entirely reflected back into the tube, with none of the light exiting to the surrounding medium. Which of the following must be true? A. θincident = 90º B. θincident = 0º C. θincident ≥ θcritical D. θrefracted = θincident - correct answer ✔✔C. θincident ≥ θcritical The question describes total internal reflection, when a light ray bounces inside a medium with a higher refractive index than the surrounding medium. For a light ray to totally internally reflect, rather than exit and refract (bend), the light ray must strike the edge of the glass tube at an angle equal or greater than the critical angle. What must be true if a light ray is totally internally reflected? - correct answer ✔✔the light must strike at an angle (incident angle) equal or greater than the critical angle What is the critical angle? - correct answer ✔✔The angle of incidence when the angle of refraction is 90 degrees

When will θrefracted = θincident - correct answer ✔✔when the index of refraction for the two media are equal What happens if the θincident = θcritical - correct answer ✔✔the light will refract to 90 degrees of the normal (travel along the boundary) how to increase / decrease solubility of gases (temp and pressure) - correct answer ✔✔To Increase the Solubility: Decrease Temp or Increase Pressure (lower energy/heat) To Decrease the Solubility: Increase Temp or Decrease Pressure (increase energy/heat) What is the molar solubility of ferrous (II) hydroxide in water at 25°C? Ksp = 3.2 x 10^- A. 2.1 x 10^- B. 8.2 x 10^- C. 2.8 x 10^- D. 2.1 x 10^-5 - correct answer ✔✔D. 2.1 x 10^- First write out dissociation equation: Fe(OH)2 + H2O -> Fe2+ + 2OH- Then write out expression Ksp = [Fe2+][2OH-]^2 = [x][2x]^2 = 4x^

Set equal to known Ksp 3.2 x 10^-14 = 4x^ x = 2 x 10^- IR spectrum of O-H - correct answer ✔✔2500-3300 cm^- IR spectrum of C=O - correct answer ✔✔1650-1750 cm^- IR spectrum of C≡C - correct answer ✔✔2100-2260 cm^- IR spectrum of C-O - correct answer ✔✔1000-1320 cm^- 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, HClO 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 ✔✔+ 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. 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^- 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

Ozonolysis - correct answer ✔✔-type of oxidative cleavage -cleaves C=C bond (ALKENE) and forms two new carbon-oxygen double bonds -tertiary will form ketone, secondary/primary will form aldehyde A single sports fan is capable of yelling at an intensity level of 80 dB from a given distance. If 10, similar fans were all yelling from the same distance, what would be closest to the observed intensity level? - correct answer ✔✔120 dB 10,000 fans would be capable of yelling at an intensity 10,000, or 10^4, times greater than the single fan alone. According to the decibel scale, this would correspond to an increase of 40 dB. The difference = 10^4 which corresponds to I/I0 therefore when you plug this into dB = 10logI/I0 -> 10log10^4 = 10*4 = 40 decibel scale - correct answer ✔✔a nonlinear scale of loudness based on the ratio of the intensity level of a sound to the intensity at the threshold of hearing dB = 10logI/I SN1 prefer what type of solvents - correct answer ✔✔polar protic SN2 prefer what type of solvent - correct answer ✔✔polar aprotic The wavelength for a standing wave is based on what? - correct answer ✔✔-whether ends are open- open, closed-closed, or open-closed -length of space Give the equation for the length of a wave in a pipe that has two open ends: - correct answer ✔✔λ = 2L / n

What are standing waves? - correct answer ✔✔-two waves of the same amplitude and frequency traveling in opposite directions Give the equation for the length of a wave in a pipe that has one closed end: - correct answer ✔✔λ = 4L / n How can you increase the wavelength of a standing wave? - correct answer ✔✔increase the length of the enclosed space How many radians are in one wavelength/360º? - correct answer ✔✔ 2 π density of water in all units - correct answer ✔✔1000 kg/m^3 = 1 g/cm^3 = 1 kg/L = 1 g/mL