You walk into a room and notice that there someone is running an experiment involving a spring-mass system. You have no idea when the experiment started, but observe that the mass attached to the spring is oscillating with period 3 (seconds) and that the amplitude of the oscillations remain constant (to your naked eye) while you are in the room. What are two differential equations which model the motion of the mass? One system must be inhomogeneous and the other must be homogeneous. Do not worry about the initial conditions.

Type into Google: "globalfoundries sand to silicon", and a Youtube video will come up (accessed on 3/17/2020). The address is:

youtube.com/watch?v=UvluuAIiA50

Watch more than once if needed.

The video will go over various parts of the process steps in making a silicon computer chip integrated circuit (IC). On this page (and on the back if needed):

1. List (in order) the major steps in the fabrication process described in the video set. I do not expect you to have a detailed description of each step – just write down the "highlights".

2. Explain why the ICs are fabricated in the "clean rooms" depicted in the video.

3. A representation of the silicon crystal is used in some of the animations in the video. Explain what is wrong with the representation.

If it has enough kinetic energy, a molecule at the surface of the Earth can escape the Earth’s gravitation.

The acceleration of gravity is 9.8 m/s2, and the Boltzmanns’ constant is 1.38066 × 10−23 J/K.

minimum kinetic energy needed to escape in terms of the mass of the molecule m, the free-fall acceleration at the surface g, and the radius of the Earth R.

1. Kmin = 1 m g R 3

2. Kmin = 1mgR 2

3. Kmin = 2 m g R 1

4. Kmin = √2 m g R 5. Kmin = m g R

020 (part 2 of 2) 10.0 points

Calculate the temperature for which the min- imum escape energy is 5 times the average kinetic energy of an oxygen molecule.

Answer in units of K.

Using energy conservation, determine the minimum kinetic energy needed to escape in terms of the mass of the molecule m, the free-fall acceleration at the surface g, and the radius of the Earth R.

1. Kmin = 1 m g R 3

2. Kmin = 1mgR 2

3. Kmin = 2 m g R 1

4. Kmin = √2 m g R 5. Kmin = m g R

020 (part 2 of 2) 10.0 points

Calculate the temperature for which the min- imum escape energy is 5 times the average kinetic energy of an oxygen molecule.

Answer in units of K.

1. Please use the equations to support your answers. What and why is the main energy consumption difference for the car driving in city or highway?

2. What is the principle for the flying and how to drive an airplane with high-energy efficiency ? Please use the equations to support your answers.

1) A cart with mass m₁ = 3.2 kg and initial velocity of v_1,i = 2.1 m/s collides with another cart of mass M₂ = 4.3 kg which is initially at rest in the lab frame. The collision is completely elastic, and the wheels on the carts can be treated as massless and frictionless. What is the velocity of m₁ in the center of mass frame after the collision?

v_f^* =

2) A block of mass M₁ = 3.5 kg moves with velocity v₁ = 6.3 m/s on a frictionless surface. It collides with block of mass M₂ = 1.7 kg which is initially stationary. The blocks stick together and encounter a rough surface. The blocks eventually come to a stop after traveling a distance d = 1.85 m . What is the coefficient of kinetic friction on the rough surface?

μ_k =

What was the value of Energyout from the Earth's surface during the Faint Young Sun era? Give your answer in W/m2, but don't write the W/m2 part.

An electric dipole is formed from 1.2 nC charges spaced 2.4 mm apart. The dipole is at the origin, oriented along the y-axis. What is the electric field strength at the following points?

(a) (x, y) = (10 cm, 0 cm)

______N/C

(b) (x, y) = (0 cm, 10 cm)

_____N/C

A m₁ = 1.00-kg aluminum block and a m₂ = 6.10-kg copper block are connected by a light string over a frictionless pulley. The two blocks are allowed to move on a fixed steel block wedge (of angle θ = 34.5°) as shown in the figure. (For aluminum on steel, μ_s = 0.61 and μ_k = 0.47. For copper on steel, μ_s = 0.53 and μ_k = 0.36.) (a) the acceleration of the two blocks and (b) the tension in the string

You are holding a shopping basket at the grocery store with a 1.24-kg carton of cereal at the left end of the basket. The basket is 0.61 m long. Where should you place a 1.9-kg

gallon of milk, relative to the left end of the basket, so that the center of mass of your groceries is at the center of the basket?

Hello ! I'm studying for a test tomorrow and looking for steps on how to do this.

A spherical shell has in inner radius R_i and an outer radius R_o. Within the shell, a total charge Q is uniformly distributed.

Calculate:

a) the charge density within the shell (if you cannot get this answer, you can proceed without it).

b) the electric field strength E(r) outside the shell (r > R_o).

c) the electric field strength inside the shell (r< R_i).

d) the electric field within the shell (R_i < r < R_o)

e) show that your solutions match both inner and outer boundaries

f) Draw a graph E versus r.

Cosmic acceleration and dark energy

Q: How do we measure the changes in the expansion rate?

Q: What is a standard candle? Why are supernovae useful as standard candles?

Q: What is so bizarre about the universe accelerating? What are the possible explanations for this? Which solution is the least radical?

Q: Why is dark energy invoked to explain the accelerated expansion?

The maximum distance from the Earth to the Sun (at aphelion) is 1.521 1011 m, and the distance of closest approach (at perihelion) is 1.471 1011 m. The Earth's orbital speed at perihelion is 3.027 104 m/s. Ignore the effect of the Moon and other planets. (a) Determine the Earth's orbital speed at aphelion. m/s (b) Determine the kinetic and potential energies of the Earth

C) A 0.315 kg bird flying along at 6.5 m/s sees a 0.019 kg insect heading straight toward it with a speed of 23 m/s (as measured by an observer on the ground, not by the bird). The bird opens its mouth wide and enjoys a nice lunch. What is the bird's speed immediately after swallowing the insect? Answer in m/s

D) A 2.6 kg block slides along a frictionless surface at 1 m/s. A second block, sliding at a faster 5.9 m/s, collides with the first from behind and sticks to it. The final velocity of the combined blocks is 2.9 m/s. What was the mass of the second block? Answer in kg