###### The Physics of Everyday Phenomena A Conceptual Introduction to Physics

68 SOLVED PROBLEMS

Question: 20.1

## Sample Exercise: Rowing With and Against the Current Two rowers, Derek and Teresa, are in a boat. Derek can row at a steady speed of 3.8 MPH, and Teresa can row at a steady speed of 4.6 MPH. If the water in the stream is moving at a speed, vwe, of 4.0 MPH relative to the bank, determine ...

We will assume that the direction of the current, ...
Question: 19.2

## Sample Exercise: Transforming Mass Energy into Kinetic Energy The nuclear masses for the reactants and products of the reaction 2He^4 + 4Be^9 ⇒ 6C^12 + 0n¹ are provided here. Using these values and Einstein’s E = mc² relationship, calculate the energy released in this reaction. ...

The mass difference is   13.014 789 u \unde...
Question: 20.3

## Sample Exercise: Adding Energy Adds Mass A Bunsen burner adds 1000 J of heat energy to a beaker of water. What is the increase in the mass of the water? ...

E = Δmc² $Δm = \frac{E}{c²}$   [...
Question: 20.2

## Sample Exercise: A Contraction in Length A spaceship traveling at the velocity of 1.8 × 10^8 m/s (0.6c) covers a distance of 900 km as measured by an observer on the Earth. a. What is the distance traveled in this time as measured by the pilot of the spaceship? b. How much time does it take to ...

From table 20.1, table 20.1 Values of γ for ...
Question: 19.1

## Sample Exercise: A Medical Isotope Technetium-99 is a radioactive isotope with a half-life of 6.0 hours that is used in bone scans and other medical tests. It emits gamma radiation. a. If a sample of technetium-99 is prepared a half-day (12 hours) before it is used, what fraction of the original ...

a. \frac{t}{t_{\frac{1}{2}}} = \frac{12  h}...
Question: 18.4

## Sample Exercise: Finding the Wavelength of a Baseball What is the de Broglie wavelength, in meters, of a 145 g baseball traveling at 80 mph? ...

p = mv                     λ=\frac{h}{p}[/l...
Question: 18.3

## Sample Exercise: Energy Levels in a Hydrogen Atom Using the energy values shown in figure 18.20, calculate the wavelength of the photon emitted in the transition from the n = 4 energy level to the n = 2 energy level in the Bohr model of the hydrogen atom. ...

The energy difference is ΔE = E_{4} - E_{2}...
Question: 18.2

## Sample Exercise: Using the Rydberg Formula What is the wavelength of the photon in the infrared series of the hydrogen spectrum for m = 6 and n = 3? Use the Rydberg formula. R = 1.097 × 10^7 m^-1 ...

\frac{1}{λ}= R (\frac{1}{n^{2}}-\frac{1}{m^...
Question: 18.1

## Sample Exercise: Burning Carbon If 30 g of pure carbon are burned (combined with oxygen) to form carbon dioxide, how many grams of oxygen will be consumed in this reaction? Carbon has an atomic mass of 12, and oxygen has an atomic mass of 16. ...

$\frac{1}{o}+\frac{1}{i}=\frac{1}{f}$...