Ice cubes at 0 c are poured into a glass that contains 150 g of liquid water at 20 c. The contents of the glass are gently stirred and after short time the ice melts and the liquid cools to 0 c. No appreciable heat exchange with the environment takes place.

a) calculate the entropy change of the universe (system plus environment) during the process. Cp=Cv = 4.18 kj/kgK
b)if the same process were performed reversibly, how much useful work would be obtained from it?

6. Solve parts a and b: A box is at rest on a horizontal, frictionless table.

a. Horizontal force F₁ points along the positive x-axis; when it is the only force acting on the box, the box accelerates at 8 m/s². Force F₂ is also horizontal; it has magnitude 5.31F₁ and acts at right angles to the direction of F₁.

If forces F₁ and F₂ act on the box at the same time, find the magnitude of the acceleration of the box now, in m/s².  

6b. A box is at rest on a horizontal, frictionless table. Horizontal force F₁ points along the positive x-axis; when it is the only force acting on the box, the box accelerates at 7.39 m/s². Force F₃ is also horizontal; it has magnitude 7.2F₁ and acts at an angle 54.3^o to the direction of F₁.

If forces F₁ and F₃ act on the box at the same time, find the magnitude of the acceleration of the box now, in m/s².  

A wheel free to rotate about its axis that is not frictionless is initially at rest. A constant external torque of +53 N·m is applied to the wheel for 21 s, giving the wheel an angular velocity of +624 rev/min. The external torque is then removed, and the wheel comes to rest 120 s later. (Include the sign in your answers.)

(a) Find the moment of inertia of the wheel.

(b) Find the frictional torque, which is assumed to be constant.

A cylinder of height 10 cm and cross sectional area of 1 cm² is submerged inside two immiscible liquids of specific gravity 1.1 and 1.0 respectively.

The cylinder is in equilibrium in such a way that 5 cm of its height is submerged in the bottom liquid and 2 cm above the surface of the two liquids.

In order the cylinder to be completely submerged inside the two liquids find the value of the mass of an object that needs to be kept on the cylinder.

A large 5-m long Tiger Shark caught off the coast of Florida was found to weigh 15000 N (on the boat). Its humongous liver was removed and found to weigh 3500 N! A subsequent buoyancy test found that the oil-filled liver has an average density of 0.92 kg/L.

a) What is the total mass of the shark?

b) What is the mass of the shark without the liver?

c) Which of the following expressions can be used for finding the overall (or 'average') density of an object made up of component B embedded in component A? (recall, p is the symbol for density)

1. paverage = p_AM_A + pBM_B / M_A + M_B

2. paverage = pA + pB / 2

3. paverage = pA + pB / 2 (M_A + M_B)

4. paverage = p_AM_A + p_BM_B / 2

d) If the shark is precisely neutrally buoyant in salty seawater of density 1.05 kg/L, what is the density of the shark WITHOUT its liver?

An electron with an initial speed of 5.05x10^5 m/s is brought to rest by an electric field. The charge of an electron is -1.60x10^-19C and its mass is 9.11x 10^-31 kg.

a) did the electron move into a region of higher electric potential or lower electric potential? Explain

b) What was the electric potential difference that stopped the electron?

Describe how to map magnetic field lines?

Two stationary positive point charges, charge 1 of magnitude 3.45 nC and charge 2 of magnitude 1.50 nC are separated by a distance of 35.0 cm. An electron is released from rest at the point midway between the two charges, and it moves along the line connecting the two charges.

What is the speed vfinal of the electron when it is 10.0 cm from charge 1?

A piston contains 620 moles of an ideal monatomic gas that initally has a pressure of 2.92 × 105 Pa and a volume of 4.1 m3. The piston is connected to a hot and cold reservoir and the gas goes through the following quasi-static cycle accepting energy from the hot reservoir and exhausting energy into the cold reservoir. The pressure of the gas is increased to 5.92 × 105 Pa while maintaining a constant volume. The volume of the gas is increased to 11.1 m3 while maintaining a constant pressure. The pressure of the gas is decreased to 2.92 × 105 Pa while maintaining a constant volume. The volume of the gas is decreased to 4.1 m3 while maintaining a constant pressure. It may help you to recall that CV C V = 12.47 J/K/mole and CP C P = 20.79 J/K/mole for a monatomic ideal gas, and that the number of gas molecules is equal to Avagadros number (6.022 × 1023) times the number of moles of the gas. 1) How much energy is transferred into the gas from the hot reservoir? J You currently have 3 submissions for this question. Only 5 submission are allowed. You can make 2 more submissions for this question.

2) How much energy is transferred out of the gas into the cold reservoir? J You currently have 0 submissions for this question. Only 5 submission are allowed. You can make 5 more submissions for this question

. 3) How much work is done by the gas? J You currently have 0 submissions for this question. Only 5 submission are allowed. You can make 5 more submissions for this question.

4) What is the efficiency of this cycle? You currently have 0 submissions for this question. Only 5 submission are allowed. You can make 5 more submissions for this question.

A 3.00-kg block of copper at 15.0°C is dropped into a large vessel of liquid nitrogen at 77.3 K. How many kilograms of nitrogen boil away by the time the copper reaches 77.3 K? (The specific heat of copper is 0.092 0 cal/g · °C, and the latent heat of vaporization of nitrogen is 48.0 cal/g.)

A 2100 kg truck is driving south through an intersection at 40 mph when it crashes into a 1200 kg car that was driving east through the intersection at 55 mph. The two vehicle stick together in a sad, scary, twisted mess. What is the velocity (both magnitude and direction) of the wreckage immediately after the collision, before the vehicles have had any time to slow due to friction?

A flat uniform circular disk (radius = 2.90 m, mass = 1.00 ✕ 10² kg) is initially stationary. The disk is free to rotate in the horizontal plane about a frictionless axis perpendicular to the center of the disk. A 40.0 kg person, standing 1.75 m from the axis, begins to run on the disk in a circular path and has a tangential speed of 2.80 m/s relative to the ground.

Find the resulting angular speed of the disk (in rad/s)
rad/s

Problem 10: Water is drawn from a well using a leaky bucket. Assume the following: • The well is 23 ft deep and requires 23 ft of rope to pull the bucket to the top. • The rope weighs a total of 12 lbs. • The bucket weighs 3 lbs when empty. • The bucket holds 16 lbs of water. It is full at the bottom of the well and loses half of its water by the time it reaches the top of the well. • The water leaks from the bucket at a constant rate. Set up an integral expression for how much work was done when pulling the bucket up the first 7 ft on its way to the top.

How are the arrangement of and movement of the particles that make up a gas different than the arrangement and movement of the particles that make up solid to liquids?

A 0.5530-kg ice cube at -12.40°C is placed inside a chamber of steam at 365.0°C. Later, you notice that the ice cube has completely melted into a puddle of water. If the chamber initially contained 6.310 moles of steam (water) molecules before the ice is added, calculate the final temperature of the puddle once it settled to equilibrium. (Assume the chamber walls are sufficiently flexible to allow the system to remain isobaric and consider thermal losses/gains from the chamber walls as negligible.)