Physics for Health Sciences

Questions: (1). For each of the two statements below, consider each of the terms listed for it and determine whether or not it can be correctly inserted into the blank. There may be more than one term that can be inserted. Explain your reasoning for your decision for each term. a. As a sound wave moves through a uniform medium, the wave will experience a gradual reduction in its __________. à ¢Ã¢â€š ¬Ã‚ ¨ Powerà ¢Ã¢â€š ¬Ã‚ ¨2. Speedà ¢Ã¢â€š ¬Ã‚ ¨3. Frequency à ¢Ã¢â€š ¬Ã‚ ¨ b. As sound moves through matter, at each compression zone there is a localized region of increased _________. à ¢Ã¢â€š ¬Ã‚ ¨ c. Particle density 2. Pressureà ¢Ã¢â€š ¬Ã‚ ¨3. Velocity (2). Patients in clinical facilities are often required to be in a partial state of undress for their procedures, and as a result may experience a drop in body temperature, particularly when the examining room temperature is low. Give two reasons for the greater rate of heat loss from the patients body when he is partially clothed in an examining gown rather than when he is fully clothed. Explain each reason. (3). You notice that the electric warming blanket that has been purchased by your clinical facility for patients has only 2 prongs to its electrical plug. a. Explain how this blanket has been designed to minimize the risk of electric shock to the user. à ¢Ã¢â€š ¬Ã‚ ¨ b. Explain why the risk of electric shock from using the blanket can be minimized by this design but à ¢Ã¢â€š ¬Ã‚ ¨ (4). A typical electric blanket consumes 50 W of power when operating. What is the overall resistance of the blanket if it is designed to be plugged into a standard powerpoint? Answers: (1). As the sound wave travels through a uniform medium, it will undergo a gradual reduction in its power. However, as the same sound waves traverse through a given medium that is uniform, its velocity remains constant because velocity depends on the characteristics of the medium. For a uniform medium, there is no change in the physical characteristics, therefore, no change in the velocity of the sound. As the sound wave is propagated through a uniform medium, it does not experience any changes in its frequency and velocity (Hindmarsh et al., 2014). As the sound waves travel across any matter, it experiences a localized region that is marked by an increase in pressure at every compression zone. The compressionof sound waves occurs when the molecules are pressed together or forced within the medium of transmission. However, when the motion of the sound wave is immense, each compression creates an excess pressure of higher amplitude compared to the decrease in pressure generated by each rarefaction. (2). Generally, the expression for computing the amount of heat loss by any given body is given as The expression is derived from the 1st Law of Thermodynamics (Zohuri and McDaniel, 2015, p. 99). There are two possible processes through which the patient in the examination can lose his body temperature when he is partially clothed compared to when he is not clothed. Heat Loss Through Radiation The normal body temperature of the patient is 37 ÃÅ'Ã…  C as a warm-blooded being. The human body temperature is higher than that of the ambient when the body is lagged by the clothing. As a result, the existing temperature gradient leads to the loss of heat from the patient to the ambient through radiation. Additionally, the head is the major point through which heat is lost to the ambient. The formula for determining the amount of heat lost by the patient what is partially dressed can be expressed as Heat Loss Through Convection When the patient is partially clothed, some parts of the body are exposed to the ambient are responsible for the rapid heat loss. The moving drought carries away the moisture droplets on the surface of the patient whose body is partially covered by clothes. The expression for computing the amount of heat dissipated by the body through convection is given as (3). The electric warming blanket is designed to reduce the risk of electric shock. The electric connector is situated at the lower end of the blanket to prevent any risks of electric shock (Bridges, Schmelz and Evers, 2007, p. 17). In addition, the blankets are designed to emit a low quantity of heat to minimize the risks of fire and other related issues. They also have many integrated safety features that help in preventing the occurrence of shock. One of such features is that they are programmed to pre-warm the bedding within certain time intervals before later switching it off. Moreover, advanced temperature controls have been installed to assist in sensing the changes in the body temperature and that of the air. The blanket further can adjust its settings appropriately and has an alert system in case of malfunction. There are, however, cases where the design features of the electric blanket cannot prevent some risks. One of the challenges is the possibility of short-circuiting the terminals of the blanket. Secondly, an electric shock may result due to damaged plugs, poor storage, and uninsulated cords. Such incidences of electric risk may occur due to the carelessness of the person using the gadget and therefore, cannot be minimized by its design features. (4). Voltage for a standard power point, V = 240 Volts For this problem, the appropriate questions are Power = Current multiplied by Voltage (Masters, 2013, p. 3-4) or the square of the current multiplied by the Resistance of the material s I = 50/240 A Therefore, Resistance, R = 50/(50/240)2 = 1152 Glossary Frequency is the number ofwavesthat passes through a point in a unit time usually one second. It is measured in hertz (Hz) whereby 1 Hz is equal to onewavein a unit second. Velocity is the product of the wavelength of a given wave and its corresponding frequency measured in m/s. Amplitude is the distance between the rest positions of a wave to its crest position. This distance equals half the vertical distance between the trough of a wave and its crest. Compression is an area within a longitudinal (sound) wave in which the particles are closer to one another. Rarefaction is a phenomenon in the transmission of the sound waves that leads to the reduction in the density of an object. A rarefaction, unlike compression, is an area of a longitudinal wave in which the particles are far apart. Convection isthe method by which heat is transferredby the mass movement of the fluid when the heated fluid is made to move away from the heat source, thereby carrying away energy with it. Radiation is the process by which the heat is transferred from a hot body to a cold body through a temperature gradient. Lagging: is the insulation of a body to prevent it from losing heat to the environment/surrounding Temperature gradient: is the difference in temperature between hot body and a cold body Ambient: is the surrounding or environment where a hot or cold object is placed Drought: is the mass of moving air through convection currents Q is the quantity of the transferred heat in a given time, t is the bodys thermal conductivity A is the area of the body Thot is the temperature of the hot body Tcold is the temperature of the cols body d is the thickness of the body Ta is the ambient temperature Tskin is the human body temperature à Ã‚ µ is the skin emissivity Au is the body region that is not covered by the clothing is a constant of the Stefan-Boltzmann Kconv is the convection constant that depends on the velocity of the wind in m/s The 1st Law of Thermodynamics: states that the overall amount of energy of a system that is isolated is constant since energy can be converted from one form to another although it can never be destroyed or created. I is the electric current measured in Amps (A) R is the resistance of the conductor, measured in Reference List Bridges, E., Schmelz, J. and Evers, K. (2007). Efficacy of the Blizzard Blanket or Blizzard Blanket plus Thermal Angel in Preventing Hypothermia in a Hemorrhagic Shock Victim (Sus scrofa) under Operational Conditions.Military Medicine, 172(1), pp.17-23. Hindmarsh, M., Huber, S., Rummukainen, K. and Weir, D. (2014). Gravitational Waves from the Sound of a First Order Phase Transition.Phys. Rev. Lett., 112(4). Masters, G. (2013).Renewable and efficient electric power systems. Hoboken, N.J.: Wiley. Zohuri, B. and McDaniel, P. (2015). First Law of Thermodynamics.Thermodynamics In Nuclear Power Plant Systems, pp.99-149.