State v. Stewart
Did she shoot him dead in self-defense?
In: Physics
1. Calculate the filling factor of a photovoltaic cell
whose dimensions are 15 cm per side, and a thickness of 200 µm of
which 99% correspond to the “p” type absorbent layer and where
there is also a amount of 13500 electrons. The thickness of the
space loading region junction is 200 nm.
The cell is subjected to standard test conditions, which produces
every second a generation of electron-hollow pairs of 2.0x10¹⁹ cm⁻³
and which translates into an increase in its density of 4.0x10¹³
cm⁻³. The efficiency of the cell is measured at 20%.
Consider that the cell is in thermal equilibrium (300K), its
prohibited band is 1.12 eV and that the mobility coefficients are
1360 cm² / Vs for electrons and 450 cm² / Vs for holes.
In: Physics
1)Describe TWO differences between viscous and inviscid flows in Balance Law of Linear Momentum.
In: Physics
In: Physics
Question 5. The 2.50 µc point charges are located on the x-axis. One is at x = 1.00 m, and the other is at x = -1.00 m. Determine the electric field on the y-axis at y = 0.500 m. Answer in Newtons per Coulombs.
Question 6. The 2.50 µc point charges are located on the x-axis. One is at x = 1.00 m, and the other is at x = -1.00 m. Calculate the electric force on a -3.50 µc placed on the y-axis at y=0.500 m. Answer in newtons.
In: Physics
Can the Hubble Space Telescope (2.4 m diameter) or the
largest optical telescope on Earth
(the Keck Telescope in Hawaii with 10 m diameter) observe manmade
items left on the moon
(e.g. the flag ~ 1.25 m long and lunar rover ~ 3 m long)? Show your
work. If not, calculate the
smallest size each telescope can resolve on the Moon and the
minimum telescope aperture
size required to resolve these objects.
In: Physics
If the Sun were to become a black hole but maintain all of its mass, what would be its Schwarzschild radius? Given this and the fact that Earth’s average distance from the Sun is about 150 million km, would the gravity of the black hole pull Earth into it? Why or why not?
In: Physics
As part of an interview for a summer job with the Coast Guard, you have been asked to help determine the search area for two sunken ships by calculating their velocity just after an accident. According to the last radio transmission from the luxury liner Apollo (3.9 × 104 metric tons), it was going due east at a steady speed of 21 knots in calm seas through a rare fog just before it was struck broadside by the freighter Blake (6.1 × 104 metric tons), which was traveling north at steady speed of 11 knots. The transmission also noted that when the freighter's bow pierced the hull of the liner, the two ships stuck together and sank. What was the speed and direction of the ships after the collision ? (Take zero degrees to be straight east and counter-clockwise as positive.)
1)____ knots
2)____ degrees
In: Physics
A 38.0-kg crate is being pushed along a horizontal surface. The applied force is 94.0 N directed at an angle of 18.0° below the horizontal and the coefficient of friction is .21.
a) Draw a free body diagram for the crate.
b) Write expressions for the x and y components of the applied force (no numbers).
c) Sum forces in the x and y direction (no numbers).
d) Solve: What is the acceleration of the crate?
In: Physics
The cube in the figure has edge length 1.20 m and is oriented as shown in a region of uniform electric field. Find the electric flux through the right face if the electric field (a) is in the positive x direction and has magnitude 7.52 N/C, (b) is in the negative y direction and has magnitude 2.68 N/C, and (c) is in the xz plane, has x component -3.16 N/C, and has z component 4.82 N/C. (d) What is the total flux through the cube's surface for each field? (a) Number Units (b) Number Units (c) Number Units (d) Number Units
In: Physics
Thermodynamics and Statistical Mechanics problem:
Write the formula for the partition function Z of an electron in a hydrogen atom. If the sum is finite, to what value does it converge? If the sum is infinite, prove it
In: Physics
A child of mass mc = 35 kg stands on the rim of a frictionless merry go round, which acts like a solid disk of mass mm = 55 kg and radius r = 1.1 m. With the merry go round at rest, they throw a rock of mass mr = 1.0 kg with a velocity v = 18 m/s relative to the ground in a direction horizontal to the ground, and tangent to the rim of the merry go round.
In: Physics
William leaves Kitchener and Mike leaves Rockwood at the same time both headed towards each others’ city along identical routes. They both have constant speeds but Mike’s is greater. They pass each other at noon without stopping. If Mike hikes into Kitchener at 1:00 PM and William reaches Rockwood at 2:15 PM at what time did they both set off? Hint: Draw a position diagram and find an equation for each distance.
In: Physics
For astronomy class, please answer this question clearly, thank you .
Titan’s atmosphere contains a large amount of photosensitive methane. We know because of basic physics and chemistry that there must be a source of methane on Titan that replenishes the atmospheric methane.
a) Describe what astronomers thought might be occurring on Titan before the Cassini/Huygens mission.
b) Describe the findings of the Cassini/Huygens mission that either supported or disproved the original hypotheses.
In: Physics
An electron is trapped in a two-dimensional region of ?? =??= 1.00x10-10 m (a typical atomic diameter). a. Find the energies of the ground state and first two excited states. b. How much energy must be supplied to excite the electron from the ground state to the second excited state? c. From the second excited state, the electron drops down to the first excited state. How much energy is released in this process?
In: Physics