When a direct current flows through a straight length of wire, what is the direction of the magnetic field that is produced near the wire?
A) The magnetic field is antiparallel to the direction of the current.
B)The magnetic field is perpendicular to the direction of the current.    
C)The magnetic field is parallel to the direction of the current.
D)There is no magnetic field near a wire carrying direct current; direct currents do not create magnetic fields.

You and a friend drag a 28.8 kg fallen tree branch across a level field. You pull with a force of 135.0 N at an angle of 25.0º above the horizontal while a friend’s pull force is parallel to the ground, the kinetic coefficient of friction between the branch and the ground is µk=0.825 and the static coefficient of friction is µs=0.925. The branch starts from rest and is dragged 20.0 m in 15.0 s.

1. What is the acceleration of the branch?
2. What is the magnitude of the normal force acting on the branch?
3. What is the magnitude of your friend’s pull force?
4. If you and your friend were to stop pulling and then your friend leaves, would you be abele to get the branch moving again with the same force? If yes, prove it, if not, what force is needed to start the branch moving?

A ball is thrown straight up with an initial speed of 19 m/s. The ball was released 6.3 m above the ground, but when it returns back down, it falls into a hole d m deep. If the ball’s speed is 35.7 m/s at the bottom of the hole, how deep is the hole (in m)?

A "Linde-machine" is used to cool and liquefy air. The cyclic process uses three different states running
through three different processes, assuming air as a diatomic ideal gas:
1 > 2: adiabatic compression with T1 = 23.0 °C, T2 = 150 °C, p1 = 2.00 x 10^5 Pa and V1 = 2.50 dm^3
2 > 3: isobaric compression with T3 = T1
3 > 1: isothermal expansion
a) Draw the corresponding p(V) diagram of the cyclic process, numbering the different states and indicating
the direction of the individual processes (note that it is not a heat engine, but used to cool air).
b) What are the number of moles, the pressure at state 2 and volumes at states 2 and 3?
c) What are the related work and heat taken up or released at each process?
d) Calculate the total amount of work.

Summarize Thermodynamics and everything you need to know/ important in a brief summary. (For physics)

The chains and sheets of galaxies and voids between them observed in the large scale structure of the universe were once thought to be contradictory with the big bang theory. Why are these observations now considered to be evidence that supports the big bang theory.

3.Consider a series RLC circuit.
a) When the capacitor is charged and the circuit is closed, find the condition for the current to be oscillatory.
b) When the circuit is connected to an AC source V = ?0 cos??, find the voltage across the inductor and the
angular frequency at which the voltage across the inductor is maximized.

Assuming a composition entirely of atomic hydrogen, and a density of
1.67x10^-19 kg/m³, use the formulae for Jeans Mass and Radius (where
appropriate), to determine which of the following gas clouds will collapse:
Cloud A: Mass = 10,000 M_sun, T = 120K
Cloud B: Mass = 7,000 M_sun, T = 80K
Cloud C: Radius = 8 pc T = 60K

A 200-g piece of ice at 0ºC is placed in 0.200 L of water at 25ºC. The system is insulated from its surroundings.

1. What is the final temperature of the system?
2. How much of the ice melts?

5: A skier, m = 65 kg, glides on a perfect hill, 10 m high, no friction. However, at the bottom is a spring, k = 1500 N/m , system to stop the skier. A silly technique I will grant you. The spring is not perfect, it loses 800 J of energy every time the spring fully compresses or extends. Now we will have to assume the spring never extends past its equilibrium position. A: What is the speed of the skier when they hit the spring the first time down the ramp? B: How much does the spring compress the first time the skier hits it? C: The skier will be pushed back up the hill so the process will continue. How many cycles (n) will occur until the skier - eventually stops?

Problem: Two blocks for masses m1 and m2 are stacked on top of each other and placed on a frictionless, horizontal surface. The surfaces between two blocks is rough and has a coeff of static friction, us. A horiz push of magnitude, F, directed to the right is applied on the bottom block.

A. Derive an expression for the maximum horizontal force, F, that can be applied on the bottom block, m1, before the top block m2, begins to slip.

B. Calculate F in Newtons (m1=5 kg) (m2=2 kg) (us=0.47)

C. If the mass of the top block is increased, what happens to the maximum value of F?

In an experiment, 300 g of aluminum (specific heat of 900 J/kg*K) at 120 Celsius is mixed with 60 g of water at 20 Celsius, with the mixture thermally isolated. You will need to look up the specific heat of water. (a) What is the equilibrium temperature? (b) What is the entropy change for the aluminum block? (c) What is the entropy change for the water? (d) What is the entropy change for the aluminum-water system?