Describe the fundamental physics of the erosion of creek beds in function of the radius of the particle.

A horizontal 808-N merry-go-round is a solid disk of radius 1.54 m, started from rest by a constant horizontal force of 50.9 N applied tangentially to the edge of the disk. Find the kinetic energy of the disk after 3.08 s.

Answer all questions in the space provided. For each problem, label all parts, show equation, substitution (with units), and answer (with units, scientific notation, rounded to 3 significant figures).

4. A string is attached between two barriers which are separated by 2.0 m. The speed of waves on the string is 150 m/s.

1. Find the wavelength 1^st harmonic of a standing wave generated between these two barriers.
2. Find the frequency 1^st harmonic of a standing wave generated between these two barriers.
3. Find the wavelength of 5^th harmonic.
4. Find the frequency of 5^th harmonic.

The speed of sound in air is 343 m/s.

1. Find the following for a 2 m wavelength sound wave.
   1. The frequency.
   2. The period.

three charged particles are placed at the corners of an equilateral triangle of side 1.20m. the charges are q1 =3.0 q2=-.85uc and q3= -6.0uc. Calculate the magnitude and direction of the net force on each s
ide due to the other two. assume the +x axis points to the right that is from q2 to q3.

q2 to q3 is along x axis q1 is above it.

please show steps.

Calculate what the Sun's rotation period should be so that its deviation from a perfect spherical symmetry was 1%.

Problem 5

a) Show that green light (λ = 5 x 10-7 m) can excite electrons across the band gap of silicon (Si).

b) i. Electromagnetic radiation of frequency 3.091 x 1014 Hz illuminates a crystal of germanium (Ge). Calculate the wavelength photoemission generated by this interaction. Germanium is an elemental semiconductor with a band gap, Eg, of 0.7 eV. ii. Sketch the absorption spectrum of germanium, i.e., plot % absorption vs. wavelength, λ.

c) Potassium (K) and beryllium (Be) are metals which exhibit good electrical conductivity. Explain for both elements the reasons for the observed conductivity on the basis of the band structure.

d) A pure crystalline material (no impurities or dopants are present) appears red in transmitted light. i. Is this material a conductor, semiconductor or insulator? Give the reasons for your answer . ii. What is the approximate band gap (Eg) for this material in eV?

e) An unknown material is transparent to light of frequencies ( ν ) up to 1.3 x 1014 s–1 . Draw a meaningful schematic band structure for this material.

(This has to do with Physics)

6.1.1 How does a capacitor charge?

6.1.2 How does a capacitor discharge?

6.1.3 What is the time constant?

6.1.4 What are the units to τ?

How are research methodologies validated?

Two skydivers are holding on to each other while falling straight down at a common terminal speed of 63.10 m/s. Suddenly, they push away from each other. Immediately after separation, the first skydiver (who has a mass of 89.30 kg) has the following velocity components (with "straight down" corresponding to the positive z-axis):

v1x=4.93 m/s      v1y=3.75 m/s     v1z=63.1 m/s

What are the x- and y-components of the velocity of the second skydiver, whose mass is 57.70 kg, immediately after separation?

What is the change in kinetic energy of the system?

What are the specific contributors to both an internal and external force? Be specific related to passive and active structures.

A delta connected load has a parallel combination of resistance 5Ω and capacitive reactance –j5Ω in each phase. If a balanced three phase 400V supply is applied between lines, find the phase currents and line currents and draw the phasor diagram

A workshop with well-insulated walls and containing 450 m³ of air at 305 K is heated at constant pressure (atmospheric). Consider air to be an ideal diatomic gas.

(a)Determine the energy (in kJ) required to increase the temperature of the air in the building by 2.90°C.

How does the amount of heat required depend on the molar specific heat at constant pressure and the desired change in temperature? What is the value for the molar specific heat at constant pressure? How can you determine the number of moles of the gas? kJ

(b)Determine the mass (in kg) this amount of energy could lift through a height 3.10 m.

Explain the difference between Ekman and Sverdrup transport. How to diagram how these work in conjunction with zonal wind stress.

Show by derivatives that two phases are in thermal equilibrium only if their temperatures are the same. Show that two phases are in mechanical equilibrium only if their pressures are equal.