Operation of the pulse oximeter (see previous problem). The transmission of light energy as it passes through a solution of light-absorbing molecules is described by the Beer-Lambert law
which gives the decrease in intensity I in terms of the distance L the light has traveled through a fluid with a concentration C of the light-absorbing molecule. The quantity ∈ is called the extinction coefficient, and its value depends on the
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- Radio station WWVB, operated by the National Institute of Standards and Technology (NIST) from Fort Collins, Colorado, at a low frequency of 60 kHz, broadcasts a time synchronization signal whose range covers the entire continental US. The timing of the synchronization signal is controlled by a set of atomic clocks to an accuracy of 101012 s, and repeats every 1 minute. The signal is used for devices, such as radio-controlled watches, that automatically synchronize with it at preset local times. WWVB's long wavelength signal tends to propagate close to the ground. (a) Calculate the wavelength of the radio waves from WWVB. (b) Estimate the error that the travel time of the signal causes in synchronizing a radio controlled watch in Norfolk, Virginia, which is 1570 mi (2527 km) from Fort Collins, Colorado.arrow_forwardAssume that you just got out of the airplane and you switched on your cell phone. If the closest BS is located at a distance of 5 kms, what is the minimum and the maximum delay before a contact is established between your cell phone and the nearest BS, given the BS transmits beacon signals every one second?arrow_forwardScientists are working on a new technique to kill cancer cells by zapping them with ultrahigh-energy (in the range of 1.00×1012 W) pulses of light that last for an extremely short time (a few nanoseconds). These short pulses scramble the interior of a cell without causing it to explode, as long pulses would do. We can model a typical such cell as a disk 5.00 μm in diameter, with the pulse lasting for 4.00 ns with an average power of 2.00×1012 W. We shall assume that the energy is spread uniformly over the faces of 100 cells for each pulse. I 1.00×1021 W/m² Submit Previous Answers Part C Correct What is the maximum value of the electric field in the pulse? ΜΕ ΑΣΦ Emax Submit Request Answer Part D ? V/m What is the maximum value of the magnetic field in the pulse? ΜΕ ΑΣΦ Bmax = Submit Request Answer ? Tarrow_forward
- (a) Suppose a star is 6.42 ✕ 1018 m from Earth. Imagine a pulse of radio waves is emitted toward Earth from the surface of this star. How long (in years) would it take to reach Earth (b) The Sun is 1.50 ✕ 1011 m from Earth. How long (in minutes) does it take sunlight to reach Earth? (c) The Moon is 3.84 ✕ 108 m from Earth. How long (in s) does it take for a radio transmission to travel from Earth to the Moon and back?arrow_forwardScientists are working on a new technique to kill cancer cells by zapping them with ultrahighenergy (in the range of 1012 W) pulses of light that last for an extremely short time (a few nanoseconds). These short pulses scramble the interior of a cell without causing it to explode, as long pulses would do. We can model a typical such cell as a disk 5.0 µm in diameter, with the pulse lasting for 4.0 ns with an average power of 2.0 x 1012 W. We shall assume that the energy is spread uniformly over the faces of 100 cells for each pulse. (a) How much energy is given to the cell during this pulse? (b) What is the intensity (in W/m2 ) delivered to the cell? (c) What are the maximum values of the electric and magnetic fields in the pulse?arrow_forward(a) Suppose a star is 7.61 ✕ 1018 m from Earth. Imagine a pulse of radio waves is emitted toward Earth from the surface of this star. How long (in years) would it take to reach Earth? years (b) The Sun is 1.50 ✕ 1011 m from Earth. How long (in minutes) does it take sunlight to reach Earth? minutes (c) The Moon is 3.84 ✕ 108 m from Earth. How long (in s) does it take for a radio transmission to travel from Earth to the Moon and back? sarrow_forward
- (a) The distance to a star is approximately 4.94 ✕ 1018 m. If this star were to burn out today, in how many years would we see it disappear? years(b) How long does it take sunlight to reach Earth? minutes(c) How long does it take for a microwave radar signal to travel from Earth to the Moon and back? (The distance from Earth to the Moon is 3.84 ✕ 105 km.) sarrow_forwardCalculate the energies of the following waves (in kilojoules per mole) An FM radio wave at 96.5 MHz and an AM radio wave at 1100 kHz Enter your answers numerically separated by a comma. ΕΧΕΙ ΑΣΦΑ EPM, EAM 1.06 10-47,1.21 10-49 Submit ° Previous Answers Request Answer X Incorrect; Try Again; 4 attempts remaining ▾ Part B ? kJ/mol An X ray with 3.40×10-9 m and a microwave with A=6.67×10-2 m. Enter your answers numerically separated by a comma. ΜΕ ΑΣΦ 0 ? 49 Ex-ray, Eairo 9.71 10 40,4.95 101 Submit Previous Answers Request Answer remaining kJ/molarrow_forwardA meteorologist is using radar to measure the distance to a storm. reception of the radar pulse is 0.23 ms. How far away is the storm? (in km) The time difference between transmission and OA: 3.71 | OB: 5.38 OC: 7.80 OD: 11.31 OE: 16.40 OF: 23.78 OG: 34.48 OH: 49.99arrow_forward
- Operation of the pulse oximeter (see previous problem). The transmission of light energy as it passes through a solution of light-absorbing molecules is described by the Beer−Lambert law which gives the decrease in intensity I in terms of the distance L the light has traveled through a fluid with a concentration C of the light-absorbing molecule. The quantity ε is called the extinction coefficient, and its value depends on the frequency of the light. (It has units of m2/mol.) Assume the extinction coefficient for 660-nm light passing through a solution of oxygenated hemoglobin is identical to the coefficient for 940-nm light passing through deoxygenated hemoglobin. Also assume 940-nm light has zero absorption (ε = 0) in oxygenated hemoglobin and 660-nm light has zero absorption in deoxygenated hemoglobin. If 33% of the energy of the red source and 76% of the infrared energy is transmitted through the blood, what is the fraction of hemoglobin that is oxygenated?arrow_forward(a) The distance to a star is approximately 4.97 × 10¹8 m. If this star were to burn out today, in how many years would we see it disappear? years (b) How long does it take sunlight to reach Earth? minutes (c) How long does it take for a microwave radar signal to travel from Earth to the Moon and back? (The distance from Earth to the Moon is 3.84 x 105 km.) Sarrow_forward(a) Suppose a star is 8.59 x 1018 m from Earth. Imagine a pulse of radio waves is emitted toward Earth from the surface of this star. How long (in years) would it take to reach Earth? years (b) The Sun is 1.50 x 1011 m from Earth. How long (in minutes) does it take sunlight to reach Earth? minutes (c) The Moon is 3.84 x 108 m from Earth. How long (in s) does it take for a high-intensity laser beam to travel from Earth to the Moon and back?arrow_forward
- Physics for Scientists and Engineers: Foundations...PhysicsISBN:9781133939146Author:Katz, Debora M.Publisher:Cengage Learning