Thermodynamics
What is the difference between internal energy and
enthalpy?
a. Give a definition for each quantity
b. Give an example of when focusing on internal energy would be
especially relevant
c. Give an example of when focusing on enthalpy would be especially
relevant.
In: Physics
Consider an equilateral triangle, inscribed in a circle of radius a, with a point charge q at each vertex. The electric field is zero at the center, but surprisingly there are three other points inside the triangle where the field is also zero. Where are they? Find the distance from these points to the center of the circle.
Please just get the answer to E in terms of a, x, and y. I only need you to solve up to the solution for E in terms of a, x, and y. Thank you!
In: Physics
Consider that you have a water park and a slide with no friction in it . Park visitors slide a vertical distance hh down the waterslide in a sitting position. When they come to the bottom of the slide, they grab a handle at the bottom end of a 5.00-m-long uniform pole. The pole hangs vertically, initially at rest. The upper end of the pole is pivoted about a stationary, frictionless axle. The pole with a person hanging on the end swings up through an angle of 70.0∘∘, and then the person lets go of the pole and drops into a pool of water. Treat the person as a point mass. The pole's moment of inertia is given by I=1/3 ML^2 , where L = 6.00 m is the length of the pole and M = 40.0 kg is its mass.
For a person of mass 70.0 kg, what must be the height hh in order for the pole to have a maximum angle of swing of 60.0∘ after the collision?
In: Physics
Light is incident upon air-water interface (n=1.33). Calculate the Brewster and critical angles for both internal and external reflections. In each case, distinguish between polarization modes. Calculate the reflectance and transmittance of water (as seen from air) for both TE and TM polarizations with the angles of incidence are 0, 45 and 90 degrees. Explain your findings. Calculate the reflectance and transmittance of air(as seen from water for both TE and TM polarizations with the angles of incidence are 0, 45 and 90 degrees. Explain your findings.
In: Physics
How can I see that the the luminosity of the sun is 3.828×1026 W by looking at the HR diagram?
In: Physics
Consider a black body of surface area 20.0 cm^2 and temperature
5 000 K. (a) How much power does it radiate?
(b) At what wavelength does it radiate most intensely?
Find the spectral power per wavelength interval at
(c) this wavelength and at wavelengths of (d) 1.00 nm
(an x- or gamma ray), (e) 5.00 nm (ultraviolet light
or an x-ray), (f) 400 nm (at the boundary between
UV and visible light), (g) 700 nm (at the boundary
between visible and infrared light), (h) 1.00 mm
(infrared light or a microwave), and (i) 10.0 cm (a
microwave or radio wave). ( j) Approximately how much
power does the object radiate as visible light?
PLEASE answer all parts!
In: Physics
Three particles A, B, and C with masses mA=2mB=mC are arranged (in that order) in a straight line. Initially, B and C are at rest a distance L apart, and A is projected towards B with speed vA. The particles then undergo elastic head‐on collisions.
SHOW THAT:
a)for any elastic head‐on collision, the relative speed of the two objects after the collision has the same magnitude (but opposite direction) as before the collision: ? vA-vB=-(vfA-vfB) ... (f for final/after collision)
b)A and B collide twice and that the time interval between these two collisions is ∆?t=12L/7vA
In: Physics
Question 5 a. Explain why liquids in a container have a meniscus. Include a discussion of all relevant forces in your answer and give examples of different forms of meniscus. [4 marks] b. i. 50 cm3 of water flows through a pipe of radius 1 cm every second. If the pressure gradient is maintained what diameter pipe is required to double the flow rate? [1 mark] ii. What is the average flow speed in each case in b(i) above? [2 marks] iii. What is the pressure gradient in the pipe? Assume water has a viscosity of 1.0x10-3 Pa s) [2 marks] iv. The original pipe branches into 5 smaller pipes of 3 mm diameter. What is the flow speed through one of the smaller pipes? [2 marks] c. A bubble of air is observed to have a diameter of 2 cm when at a depth of 1.5 m in a swimming pool. What is the total pressure of air inside the bubble? The surface tension of water is 0.073 N m-1 and the density of water is 1000 kg m-3 . [2 marks] d. Explain the differences between the terms Elastic Limit, Compressive Limit, Tensile Strength and Compressive Strength. [3 marks] e. Explain the process of cavitation and give an example of its occurrence. [4 marks]
In: Physics
A ball, which is initially at rest, starts rotating around a fixed point. The ball has a constant angular acceleration. You need to know that the radial acceleration of the ball aradarad is proportional to ball's angular displacement θ
Find the angular displacement of the ball if its resultant acceleration makes an angle of 40 ∘ with the radial direction?
In: Physics
You must provide a brief description of the obstacle you design, highlighting the physical concepts involved and explicitly stating the relevant formulas that are at work. If there’s a specific strategy that would be most effectively for completing the obstacle, include a description of it. Using: Rotation Thank you so much.
In: Physics
A small block with mass 1.50 kgkg is placed against a light spring that is compressed 0.250 mm. The spring has force constant 50.0 N/mN/m . The block and spring are released from rest, and the block travels along a horizontal surface for which the coefficient of kinetic friction between the block and surface is μkμk = 0.500. When the block has moved 0.250 mm and the spring has reached its equilibrium length, the block loses contact with the spring.
Find the speed of the block at the instant when it leaves the spring?
Calculate the maximum speed of the block during its motion?
In: Physics
Algunos espejos nos dan imágenes reales, virtuales, más grandes, más pequeñas, dependiendo de donde se ubiquen los objetos y de las características del espejo. La amplificación de cierto espejo es 2.5 para algún objeto de 3.0 cm de alto, que está alejado 10 cm del espejo.
In: Physics
2a. Confirm that the position and momentum, p=-ℏ ∂/∂x, operators do not commute.
2b. Show how the statement above limits the ability for a state that to be both an eigenstate of position and momentum concurrently.
2c. For an eigenstate where the momentum is zero, show that x than p leads to a result, xp, that is different than that of p then x.
In: Physics
Calculate how far apart an electron and a proton would have to be for their electric force to be equal in magnitude to their gravitational force in a hydrogen atom (a distance of 52.9pm). Give the answer in meters. Then convert meters to light-years given that the speed of light is 2.998*108 m/s and a year is approximately 365.2421 days, and a light year is the distance light travels in one year.
In: Physics
Using the wave functions
| ψ0(x) = A'eik0x + B'e−ik0x | x < 0 | |
| ψ1(x) = C'eik1x + D'e−ik1x | x > 0 |
for the potential energy step, apply the boundary conditions of ψ and
dψ/dx
to find B' and C' in terms of A', for the potential step when particles are incident from the negative x direction. Evaluate the reflection and transmission coefficients
R=
| |B'|2 |
| |A'|2 |
and
T=
| k1|C'|2 |
| k0 |A'|2 |
.
( k0=42 and k1=12)
| B' | = ? A' | ||||
| C' | = ? A' | ||||
R=
|
= ? | ||||
T=
|
= ? | ||||
|
R+T |
= ? |
In: Physics