A block with mass mA = 15.0 kg on a smooth horizontal surface is connected by a thin cord that passes over a pulley to a second block with mass mB = 6.0 kg which hangs vertically.

Determine the magnitude of the acceleration of the system.

Express your answer to two significant figures and include the appropriate units.

If initially mA is at rest 1.250 m from the edge of the table, how long does it take to reach the edge of the table if the system is allowed to move freely?

Express your answer to two significant figures and include the appropriate units.

If mB = 1.0 kg, how large must mA be if the acceleration of the system is to be kept at g100?

Express your answer to two significant figures and include the appropriate units.

Two small forward-facing speakers are 2.50 m apart. They are both emitting, in phase with each other, a sound of frequency 1100 Hz in a room where the speed of sound is 344 m/s. A woman is standing opposite the midpoint between the speakers and is initially 35.0 m from the midpoint. As she slowly walks parallel to the line connecting the speakers, at what angle θ (relative to the centerline coming outward from the midpoint between the speakers) will she first hear no sound?

Q2) A 400-gram package lying on a horizontal surface is attached to a horizontal string which passes over a smooth pulley. When a mass of 200 grams is attached to the other end of the string, the package is on the point of moving. Find μS, the coefficient of static friction

Where there are multiple forces acting on the same object, draw a free-body diagram (i.e a diagram where each vector for each of the different forces is shown): A book on a table has a coefficient of static friction of 0.1 and a coefficient of kinetic friction of 0.05. The book has a mass of 1kg. The table has a length of 3m. Suppose you gently tilt the table until the book starts to slip and then leave the angle of the book at that critical angle afterwards. How long will it take the book to slide to the end of the table?

An electron and a positron are located 17 m away from each other and held fixed by some mechanism. The positron has the same mass and the same magnitude of charge as those of the electron, but its charge is positive. The electron and the positron are released at the same time by the mechanism. The electron and the positron begin to speed up towards each other. What velocities should they have when they are 1.3 m away from each other?

QUESTION 1:

Two point masses are the same distance R from an axis of rotation and have moments of inertia I_A and I_B.

(a)

If I_B = 4I_A, what is the ratio

of the two masses?

=

(b)

In terms of R, at what distance from the axis of rotation should mass A be placed so that

I_A = I_B?

R

QUESTION 2:

A large grinding wheel in the shape of a solid cylinder of radius 0.330 m is free to rotate on a frictionless, vertical axle. A constant tangential force of 230 N applied to its edge causes the wheel to have an angular acceleration of 0.980 rad/s².

(a) What is the moment of inertia of the wheel?
kg · m²

(b) What is the mass of the wheel?
kg

(c) If the wheel starts from rest, what is its angular velocity after 4.60 s have elapsed, assuming the force is acting during that time?
rad/s

Apply the Pauli exclusion principle to determine the number of electrons that could occupy the quantum states described by the following.

a) n = 4, ℓ = 3, mℓ = −2

b) n = 4, ℓ = 2

c) n = 4

Your 300mL cup of coffee is too hot to drink when served at 90.0 ∘C.

A)What is the mass of an ice cube, taken from a -16.0 ∘C freezer, that will cool your coffee to a pleasant 58.0 ∘?

5. A proton and an electron are in a uniform electric field with magnitude 45 V/C. Which particle has the larger magnitude acceleration, and what is the magnitude of the acceleration? (e = 1.6×10−19 C, mp = 1.67×10−27 kg, me = 9.11×10−31 kg) A. the electron, 7.9×1012 m/s2 B. the proton, 4.3×1013 m/s2 C. the proton, 4.3×109 m/s2 D. the electron, 7.9×108 m/s2 E. the electron, 7.9×1010 m/s2

6. A +2q point charge is located at the origin (x = 0), and a –3q charge is at x = +d. What is the magnitude of the electric field at x = +2d ? Assume 1 4π0 = k. A. 7kq 2d2 B. 5kq 2d2 C. 4kq d2 D. 3kq 2d2 E. 5kq d2

A mass m = 17 kg is pulled along a horizontal floor with NO friction for a distance d =5.7 m. Then the mass is pulled up an incline that makes an angle θ = 34° with the horizontal and has a coefficient of kinetic friction μk = 0.38. The entire time the massless rope used to pull the block is pulled parallel to the incline at an angle of θ = 34° (thus on the incline it is parallel to the surface) and has a tension T =83 N.

What is the work done by tension before the block goes up the incline? (On the horizontal surface.)

What is the speed of the block right before it begins to travel up the incline?

What is the work done by friction after the block has traveled a distance x = 2.6 m up the incline? (Where x is measured along the incline.)

What is the work done by gravity after the block has traveled a distance x = 2.6 m up the incline? (Where x is measured along the incline.)

How far up the incline does the block travel before coming to rest? (Measured along the incline.)

A common solution to the wave equation is E(x,t) = A e^^i(kx+wt). On paper take the needed derivatives and show that it actually is a solution. Note that i is the square-root of -1.

Five kilograms of ammonia (NH3) undergo a refrigeration cycle
detailed as:
• Process 1-2: isothermic expansion from saturated vapor at 10ºC, to P = 3 bar with
Q = 400 kJ.
• Process 2-3: isochoric cooling to 0 ◦C.
• Process 3-4: isobaric compression.
• Process 4-1: isochoric heating.

Calculate:

a) the P −v and T −v diagrams.

b) the states table detailing P, v, T and u.
c) the process table for Q, W and ∆U.
d) the performance coefficient, β, of the cycle.

Consider two spherical shells with radii R1 < R2 with the inner shell having the potential Φ(ϑ)=Φ1×cos^2(ϑ), ϑ being the azimuthal angle in spherical coordinates. The outer shell is metallic and uncharged (Q2 = 0). Calculate the potential Φ(r) on the entire space. Thanks a lot.

1. Distinguish between inertial and accelerated frames of reference.

2.Consider two days when the air temperature is the same but the humidity is different. Which is more dense, the dry air or the humid air at the same T?