Identify one function of the guard ring in an ionisation chamber?

Infrared radiation is also called IR. Describe how it is different from visible light. What emits IR? Can animals use it? Explain how emission of IR sometimes “wastes” energy. Give examples showing how IR is used in modern technology.

Explain why the shape of the Fourier amplitude spectrum depends on magnitude. Keep your answer concise by using sketches and/or equations.

Two friends Colby [mass mC = 34 kg] and Charlie [mass mCh = 42 kg] are avid swimmers. Colby is a master swimmer, while Charlie only swims recreationally. They both start on one side of pool (x = 0) at the same time (t = 0). The pool is separated into lanes along the “long course” so that the other end is at x = 50 m. Colby swims 2,500 m in 55 minutes; we assume that Colby and Charlie swim at constant speeds. a) Colby and Charlie “meet” for the second time when they are at x = 11 m after Colby makes two turns and Charlie makes only one turn. When [i.e., at what time] do Colby and Charlie meet?

b) Sketch the position vs. time graph for Colby and Charlie until they “meet” the second time.

c) How fast does Charlie swim?

d) Where do Colby and Charlie meet for the first time?

e) How long does Colby have to wait until Charlie finishes the total distance 2,500 m?

FOR PULSE OXIMETER:

1. The overall purpose of the device and clinical condition it looks to diagnose or treat

2. What type of biosignal the device records and how that signal originates in the body and where (comment on SI

units, range, variability)

3. The underlying electronic circuitry and rationale behind the signal processing

4. Typical sensitivity/specicity performance of the device

(PLEASE BE SPECIFIC AND WRITE OUT DETAILED ANSWERS.)

Harry is a HS student with too much time on his hand when he was homebound during the COVID-19 pandemic. He designed a method how he can throw pebbles over the 2.1-m fence in his backyard such that they land in a pot on the ground of his neighbor’s property: he stands 6.7 m in front of the fence and throws a pebble from 1.7-m height such that the highest point is at 1.5 m right above the fence.

a) We use t1 for the time for the pebble to travel from Harry’s hand to the highest point and t2 for the time for the pebble to travel from the highest point until it falls into the pot. Find the ratio t1/t2!

b) Find the distance D of the pot from the fence!

c) Find the launch speed of the pebble!

d) Find the direction in which he throws the pebble!

2. 2D Density of States (~Kasap 4.9)

Kasap Section 4.5 (in 4th Ed.) derives an expression for the density of states for electrons in a 3D infinite potential well (3D Sommerfeld box). This derivation is similar to the one we did in class.

a. Following the approaches used in the 3D derivations, consider an electron confined to a 2D infinite potential well and derive an expression for the 2D density of states, g_2D, which is the number of states per unit area per unit energy with energy E between E and E+dE.

(Hint: you might start by solving the 2D Schrödinger Eqn. to determine the allowed k-space values, which you could then plot and use to guide your derivation.)

14. (16) Greg

A proton moving at 40 m/s due East collides with another proton at rest. Assume the collision is elastic and glancing. After the collision, one proton moves 30◦ south of East. Find the magnitude an direction of the other proton after the glancing collision

How do digital signals work?

I am trying to explain how a simple coil speaker works, I understand that a current creates an electromagnet in the coil whose magnetic field interacts with that that of the permanent magnet... however I am confused as to how the electricity is sent from the phone and into the coil, can someone explain this please?

Does this relate to motion of waves? are they electromagnetic waves being converted in to vibrational waves? im confused!!!

Intermodal. What are some of the challenges in designing pallet loads if half of your shipments go by 53 ft. containers to customers in North America, and half of your shipments go by 40 ft. containers to international clients? Assume inside dimensions for a 53 ft. container are approximately 52 ft. 6 in. long x 8 ft. 2 in. wide x 9 ft. high.

1b) Suppose z is any positive even integer. Write a formula in terms of z that gives the total number of palindromes of length z using characters from a set that contains 40 different symbols. A palindrome is a string of characters that are the same from left to right and right to left.

1c) Suppose z is any positive odd integer. Write a formula in terms of z that gives the total number of palindromes of length z using characters from a set that contains 40 different symbols. A palindrome is a string of characters that are the same from left to right and right to left.

If you show your work and explain, I will like your answer!

A circular conducting loop is held fixed in a uniform magnetic field that varies in time according to B(t) = B exp(-at) where t is in s, a is in s^-1 and B is the field strength in T at t = 0. At t = 0, the emf induced in the loop is 0.0614 V. At t = 2.74 s, the emf is 0.0197V. Find a.

While an astronaut on planet X, you find a sample of an unknown liquid. Without your fancy equipment you decided to measure the mass of your spoon (25 grams, using local gravity) in and out of the liquid. In the liquid the scale reads 17.3 grams and it reads 18.9 grams in water. What is the density and the identity of the unknown liquid?

A 14 g circular annulus of outer radius 41.8 cm and inner radius 26 cm makes small oscillations on an axle through its outer edge perpendicular to its face.

(a) Find its frequency of oscillation.


(b) Find the frequency of oscillation of a thin ring of the same outer radius and mass.


(c) Find the frequency of oscillation of a solid disc of the same outer radius, thickness, and density.