A flat sheet of chrystalline quartz has a thickness of 2.48 cm. It is on top of a flat sheet of fused quartz that has a thickness of 1.50 cm. Light strikes the chrystalline quartz perpendicularly and travels through it and then through the fused quartz. In the time it takes the light to travel through the two sheets, how far (in cm) would it have traveled in a vacuum?

1.You measure the velocity of an electron to an accuracy of ±22.6 m/s. What is the minimum uncertainty in its position? (h = 6.626 × 10-34 J ∙ s, melectron = 9.11 × 10-31 kg)

A 32.2 μm

B4.03 μm

C5.12 µm

D 8.05 μm

E16.1 μm

2.A 10-g bouncy ball is confined in a 8.3-cm-long box. What is its minimum energy? (h = 6.626 × 10-34 J ∙ s)

A.8.1 × 10-65 J

B.9.4 × 10-75 J

C.3.2 × 10-46 J

D.1.3 × 10-20 J

I am doing an experiment recording the speed of sound. I am using an open-ended cardboard tube that is 76.2cm (30") and the temperature in my room is 75 degrees or 23.89 celsius.

What is my speed of sound (using the speed of sound expression with explanation please)?

Given the length of my tube, what are my first five wavelengths that my tube should resonate (using the standing sound wave formula)?

What are my five wavenumbers (k) of the above (reciprocal).

What should  my first five resonance frequencies (predicted) be? If i understand this correctly, I do this using the theoretical speed of sound calculated above together with the five resonance wavelengths also determined above.

The average thermal energy of a particle is ~ k_BT where k_B is Boltzmann’s constant and T is the temperature in degrees Kelvin. At room temperature, k_BT = 25 meV = 4.1 x 10-21 J = 4.1 pN – nm =0.6 kcal/mole (eV = electron volts; J = Joules, N = Newtons; kcal = kilocalories).

a. A typical molecular motor uses 100 to 1000 ATP molecules per second. Calculate how much energy is dissipated in the motor (in Watts, or J/s). Call this power quantity M.

b. Nuclear vibrations occur on the time scale of 10^-13 sec. Compute the scale of power input to a molecular motor from random collisions with surrounding water and call it R, assuming that the collisions transfer about k_BT of energy each. Estimate the ratio R/M.

c. How does your estimate differ if you assume that water molecules require a diffusion time given by Δx²/D to transfer k_BT of energy to the motor, where Δx is the average distance between water molecules in solution?

“High voltage” power lines are often seen suspended high above the ground. Two of these power lines are suspended above a physics professor who is out for a walk. The power line on the left carries a current out of the page; the power line on the right carries a current into the page.

a) What is the direction of the magnetic field produced by the two currents at the location of the physics professor? He is on the ground halfway between the two wires. Draw a diagram illustrating your reasoning. Hint: Determine the direction of the magnetic field produced by each current separately, then add them together.

b) The physics professor has been shuffling his feet on the ground as he walks to the right which has made him become negatively charged. Determine the direction of the magnetic force (if any) exerted by the magnetic field on him. Explain your reasoning.

c) Does the power line on the left exert a force on the power line on the right? Explain your reasoning. If you think it does, determine its direction.

An ambulance traveling eastbound at 144.0 km/h with sirens blaring at a frequency of 7.50 ✕ 10² Hz passes cars traveling in both the eastbound and westbound directions at53.0 km/h. (Assume the speed of sound is 343 m/s.)

(a) What is the frequency observed by the eastbound drivers as the ambulance approaches from behind?
_______Hz

(b) What is the frequency observed by the eastbound drivers after the ambulance passes them?
_______Hz

(c) What is the frequency observed by the westbound drivers as the ambulance approaches them?
________ Hz

(d) What is the frequency observed by the westbound drivers after the ambulance passes them?
_________ Hz

A high-energy photon in the vicinity of a nucleus can create an electron-positron pair by pair production:

γ → e⁻ + e⁺.

(1) What minimum energy photon is required?
_____________MeV

(2) Why is the nucleus needed?

a)Electrons can only exist inside the nucleus. b)Positrons can only exist inside the nucleus. c)The nucleus is required to absorb the energy so that conservation of energy is not violated. d)The nucleus is required to absorb the momentum so that conservation of momentum is not violated.

1. If you are given an equipotential diagram, how could you use it to figure out the direction of the electric field at a specific location? Explain your thinking in detail, using both words and a picture.

2. If you are given an equipotential diagram, how could you use it to figure out which regions have a stronger electric field and which regions have a weaker electric field? Explain your thinking in detail, using both words and a picture.

In the shot put, a heavy lead weight—the "shot"—is given an initial velocity, starting from an initial elevation approximately equal to the shot putter's height, say, 2.00 m. If v₀ = 7.90 m/s, find the horizontal distance traveled by the shot for the following initial angles above the horizontal. (a) θ₀ = 0°


(b) θ₀ = 40.0°


(c) θ₀ = 45.0°

A concave spherical mirror with a focal length of 12 cm faces a plane mirror with the optical axis of the spherical mirror perpendicular to the plane mirror. A small object is placed at point P on the optical axis, 11 cm from the plane mirror and 29 cm from the vertex of the spherical mirror. Find the distance from the plane mirror to the three nearest images. (Enter your answers from smallest to largest.)

An astronaut finds herself in a predicament in which she has become untethered from her shuttle. She figures that she could get back to her shuttle by throwing one of three objects she possesses in the opposite direction of the shuttle. The masses of the objects are 5.4 kg, 7.9 kg, and 10.1 kg, respectively. She is able to throw the first object with a speed of 15.00 m/s, the second with a speed of 10.6 m/s, and the third with a speed of 5.5 m/s. If the mass of the astronaut and her remaining gear is 75.0 kg, determine the final speed of the astronaut with respect to the shuttle if she were to throw each object successively, starting with the least massive and ending with the most massive. Assume that the speeds described are those measured in the rest frame of the astronaut.

At each position in a 3D grid lies an atom with a positive or negative spin, specified by values +1 and -1, respectively. The spin value at each position is assigned randomly based on whether a randomly generated number is greater than or less than 0.5. I need to plot a 3D visualization of this grid using MATLAB in which positive spin locations are represented by markers of one color and negative spin locations are another color.

A platinum sphere with radius 0.0115 m is totally immersed in mercury. Find the weight of the sphere, the buoyant force acting on the sphere, and the sphere\'s apparent weight. The densities of platinum and mercury are 2.14

A boy tosses a football upward. If the football rises a vertical distance of 6.9m and the boy catches it at the same point he released it, what is the velocity of the ball just before he catches it? (Assume upward is the positive direction. )

A car accelerates uniformly from rest and reaches a speed of 23.0 m/s in 8.96 s. Assume the diameter of a tire is 57.9 cm.

(a) Find the number of revolutions the tire makes during this motion, assuming that no slipping occurs.
   

(b) What is the final angular speed of a tire in revolutions per second?
rev/s