A person takes 15 minute showers in 100°F water using a 2.0 gallon per minute shower head. Ignoring losses, how many cubic feet of natural gas did the shower need if the house has a 40,000 BTU/hour water heater? The incoming water temperature is 50°F. Is it possible for this person to complete this shower without the water temperature dropping?

Consider a system of four nonidentical spin 1/2 particles. Find the possible values of the total spin of this system and state explicitly the number of angular momentum eigenstates for each of the total spin values.

An ideal flow can be described by a velocity potential . What does express? Illustrate (choose your own flow example) how you with help of the velocity potential and equipotential lines can find the flow direction and if the flow velocity increase, is constant or decrease

Two point charges lie on the x axis. A charge of + 2.50 pC is at the origin, and a charge of − 4.70 pC is at x=−12.0cm. What third charge should be placed at x=+24cm so that the total electric field at x=+12.0cm is zero?

Two people start at rest from the same point on a circular track of radius R = 20 m. Person #1 runs counterclockwise around the track with a con- stant angular acceleration of α1 = 0.0010 rad/s2. At the same time, Person #2 runs clockwise around the track with a constant angular acceleration of α2 = 0.0025 rad/s2. Determine the speed of each person when they meet for the first time after they start running.

I know from the class to start by finding time when they meet using |θ1| + |θ2| = 2π   yielding 1/2 α1(T)^2= 1/2 α2 (T)^2

can you please solve this problem

Also explain why |θ1| + |θ2| = 2π and

Where this equation come from 1α1T2 + 1α2T2 = 2π

Find the temperature distribution T(r,θ,z) inside a cylinder of height z= 20 and radius r= 8 , if the cylinder temperature is zero in all surface except the bottom circular surface where it is divided two halves , the first is held at T1= 100 c and the other is held at T2=200 c.

please use laplace equation and show me the solution with the details of the derivation .

How can I conduct an home experiment to explore:

How thick is the liquid water film beneath a sliding ice cube?

why does the wiedemann franz law always work at high temperatures? why are the scattering processes simular at that range, and what would happen if a electric field is applied

how does the linearized boltzmann equation affect transport properties

give the equation for current density in form of fermi dirac distribution function and graph it

1.carry out the dimensional analysis of a simple pendulum
2.The dimensional analysis of walking
3.Dimensional analysis of a solid sphere moving through a fluid

(4) Consider a system described by the Hamiltonian H, H = 0 a a 0 !,
where a is a constant. (a) At t = 0, we measure the energy of the system, what possible values will we obtain? (b) At later time t, we measure the energy again, how is it related to its value we obtain at t = 0 ? (c) If at t = 0, the system is equally likely to be in its two possible states, write down the most general state of the system at t = 0. (d) What is the probability that at time t = 5, the system will be in a state different from its initial state?. (e) Suppose the above Hamiltonian describes a spin-1/2 particle in a magnetic field. If Sx is found to be ¯h/2, what is the probability of getting Sz equal to ¯h/2?. What is the probability of getting Sy equal to −¯h/2 ? What is the probability of getting Sx equal to −¯h/2
2

Indicate whether the following statements are always true or can be false.
True False  If an object's speed does not change, no net force is acting on the object.
True False  If two objects are under the influence of equal forces, they have the same acceleration.
True False  The net force which acts on an object which maintains a constant velocity is zero.
True False  An object's velocity will change if a net force acts on the object.
True False  A truck initially moving at a constant velocity will slow down unless a small net force is applied.
True False  During the collision of a car with a large truck, the car exerts a lesser force on the truck than the truck exerts on the car.

Solid-state physics, Band gap

a, How does the size of the band gap depend on the strength of the periodic potential?

b, Which type of material would you expect to have the stronger periodic potential, a metal or an insulator? Why?

Please explain thoroughly

A metal surface is susceptible to a photoelectric threshold frequency of 8.529*10>14Hz. Will the monochromatic UV light sources of wavelengths 283 nm, 342 nm, and 363 nm be able to eject photoelectrons from the metal. If so what is the speed of the fastest electron ejected?