Question The figure shows a spherical nonconducting shell carrying a net positive charge \( 20 \mu \mathrm{C} \) uniformly distributed through its volume. It has an inner radius \( a=2.5 \mathrm{~cm} \) and outher radius \( b=8 \mathrm{~cm} \). Using Gauss' law, Part B - Find the magnitude of the electric field at radial distance \( r=5 \mathrm{~cm} \) Express your answer numerically, to two significant figures, using \( \epsilon_{0}=8.85 \times 10^{-12} \mathrm{C}^{2} /\left(\mathrm{N} \cdot \mathrm{m}^{2}\right) \). \[ E(r=5 \mathrm{~cm}) \] Part C - Find the magnitude of the electric field at radial distance \( r=12 \mathrm{~cm} \) Express your answer numerically, to two significant figures, using \( \epsilon_{0}=8.85 \times 10^{-12} \mathrm{C}^{2} /\left(\mathrm{N} \cdot \mathrm{m}^{2}\right) \). \[ E(r=12 \mathrm{~cm}) \]

A ball with mass \( m=1.72 \mathrm{~kg} \) is attached to a frictionless swivel at point C using a string of length \( L=1.54 \mathrm{~m} \). It is kicked horizontally at the top of a vertical circle, so that its initial speed is \( v_{0}=4.50 \mathrm{~m} / \mathrm{s} \), directed as shown in the figure. The earth's gravitational force on the ball points down, as usual, and the mass of the string is negligible. Defining the angle as shown, what is the ball's speed at \( \theta=21.7^{\circ} \) ? \[ v=\quad \mathrm{m} / \mathrm{s}(\pm 0.02 \mathrm{~m} / \mathrm{s}) \]

please help! The energy of a photon is related to its frequency through the following equation \[ E=h v \] where \( E \) is the energy, \( h \) is Planck's constant, and \( v \) is the frequency. Rearrange the equation to solve for \( v \). A photon has an energy of \( 4.10 \times 10^{-19} \mathrm{~J} \). What is the frequency of the photon?

An object with total mass mtotal = 17.3 kg is sitting at rest when it explodes into three pieces. One piece with mass m1 = 4.9 kg moves up and to the left at an angle of θ1 = 20° above the –x axis with a speed of v1 = 25.5 m/s. A second piece with mass m2 = 5.1 kg moves down and to the right an angle of θ2 = 25° to the right of the -y axis at a speed of v2 = 21 m/s. What is the x-component of the velocity of the third piece? What is the y-component of the velocity of the third piece? What is the magnitude of the velocity of the center of mass of the pieces after the collision? Calculate the increase in kinetic energy of the pieces during the explosion.

3. Write Java code for a Baby class. A Baby has a name of type String and an age of type integer. Supply two constructors: one will be the default constructor, which just sets default values for the name and age; the second constructor will take two parameters, a string to set the name and an integer to set the age. Also, supply methods for setting the name, setting the age, getting the name and getting the age. The class should not contain I/O methods; use set method or constructor to set the value passed in as a parameter. The instance variables for output can be obtained using the get methods. The set method for the name instance variable should ensure that the value passed is not empty or contain whitespaces (otherwise set a default value). The set method for the age instance variable should validate the value passed to be between 1 and 4 inclusive (otherwise set a default value). Give Java code for an equals method for the Baby class. Babies count as being the same (i.e. equal) if their names and their ages are exactly identical (names should not be case sensitive). The method will take a Baby type parameter and use the calling object (thus comparing these two objects via name and age); it should return Boolean - true or false as appropriate. Remember, if comparing Strings, you must use String comparison methods. 4. Test your Baby class by writing a client program which uses an array to store information about 4 babies. That is, each of the four elements of the array must store a Baby object. If you have an array for baby names and another array for baby ages, then you have missed the point of the exercise and therefore not met the requirement of this exercise. A Baby class object stores the required information about a Baby. So each Baby object will have its own relevant information, and thus each object must be stored in one element of the array.

For a Solid Oxide Fuel Cell stack that uses hydrogen as fuel and operates at 800°C (same as question 1 of Homework 9), if the inlet hydrogen flow rate is 20 mol/min, hydrogen conversion is 60%, and 60% of the produced energy can be converted into electrical energy, what would be the power output of the stack in kW.

For a Solid Oxide Fuel Cell stack that uses hydrogen as fuel and operates at 800°C (same as question 1 of Homework 9), if the inlet hydrogen flow rate is 20 mol/min, hydrogen conversion is 60%, and 60% of the produced energy can be converted into electrical energy, what would be the power output of the stack in kW.