1. A 4500 kg ore car accelerates at 0.4 m/s² up a ramp which has a 9 % grade. If the coefficient of friction µ_k = 0.25, calculate the force applied on the ore car. (4 points)

please type your answer, Please do not write on the paper and post it

A block of mass m1 = 4.15 kg is released from circled A. It makes a head-on elastic collision at circled B with a block of mass m2 = 10.5 kg that is initially at rest. Calculate the maximum height to which m1 rises after the collision.

Two 13-cm-diameter electrodes 0.56 cm apart form a parallel-plate capacitor. The electrodes are attached by metal wires to the terminals of a 11 Vbattery. After a long time, the capacitor is disconnected from the battery but is not discharged. What are the 1-----

a) charge on each electrode, b) the electric field strength inside the capacitor, and c) the potential difference between the electrodes right after the battery is disconnected?

2-----

What are a) the charge on each electrode, b) the electric field strength inside the capacitor, and c) the potential difference between the electrodes after insulating handles are used to pull the electrodes away from each other until they are 1.1 cm apart?

3-------

What are a) the charge on each electrode, b) the electric field strength inside the capacitor, and c) the potential difference between the electrodes after the original electrodes (not the modified electrodes of parts D-F) are expanded until they are 26 cm in diameter?

Question 4

An interesting topic in fluid mechanics is Bernoulli's equation, which relates pressures and velocities of a fluid with the density of rho at different heights, eq. 13.12. It has applications in the airspace. It can be used to measure flow speed in a pipe with a device named the Venturi meter (see figure 13.34). If the cross sections are 21 cm2 and 13 cm2, and the height difference resulted from the pressure difference is 0.2 m, calculate the speed of the flow in the pipe, v1 . Give your answer to one decimal point. Your Answer:Question 4 options:

Answer units

When vertically falling sand lands in a horizontally moving cart, the cart slows. Ignoring friction, give two reasons for this, one in terms of a horizontal force acting on the cart and one in terms of momentum conservation.

b) In a movie, the hero jumps straight down from a bridge onto a small boat that continues to move forward with no change in velocity. What physics is being violated here?

The spinning Earth is slowing down. Our days are getting longer. The effect is real, and so we have to add "leap seconds" to our clocks every 100 years to account for it. What is causing this? Also, why is the distance between the Earth and Moon increasing? Use physical concepts.

Why are the following statements false?

The potential energy of a system of interacting particles equals the sum of the potential energies of the individual particles.

The value of the integral ( - pdV) is fixed once the values of the initial and final states(1 and 2) are established.

For a closed system at rest with no fields present, the sum q+w has the same value forevery process that goes from given state 1 to given state 2.

For a constant volume process in a closed system,H=U.

Cp is a state function.

1) Object "A" has twice the weight of object "B" at a given point on the moon's surface. "A" must have twice the mass of "B".  True or False

2) The two objects above are moved to Mars. At the same place on the surface of Mars, the weight of "A" will be twice that of "B."  True or False

3) For a given object composed of a known material on a known surface, the  coefficient of kinetic friction is usually expected to be greater than the coefficient of static friction. True or False

4) A ball is dropped from an LWIT baloney. While falling, more than one force acts on it in the vertical direction. Identify the forces and select all the correct answers below.
a)Gravity
b) Normal Force
C) Tension
d)Lift
e) Friction

5) If there are only two forces on the above ball while falling and if their magnitudes are the same but their directions are opposite, then the ball's vertical velocity is constant. True or False

6) For the conditions in the question directly above, the ball is not accelerating and it is in equilibrium. True or False

7) The above ball's mass is 2.041 kg. What is the magnitude of the gravitational force acting on it?

8) If friction is neglected, what is the magnitude on the ball's acceleration in the vertical direction?(in m/s²)

A 12.0-kg package in a mail-sorting room slides 2.00 m down a chute that is inclined at 53.0∘53.0∘ below the horizontal. The coefficient of kinetic friction between the package and the chute’s surface is 0.40.

I know hot to calculate Work for each separate force on the package. But how would you use the Work Kinetic Energy Theorem to find the package's change in kinetic energy?

Thanks!

Below is a diffraction problem. I have the solutions to the problem but I don't know how to arrive at these solutions.

A) In an experiment two slits are separated by 0.22mm and illuminated by light of wavelength 640nm. How far must a screen be placed in order for the bright fringes to be separated by 5 mm? (1.72 m)

B) A soap film is illuminated by white light normal to its surface. The index of refraction of the film is 1.50. Light corresponding to a wavelength in air of 600 nm is intensified in the reflected beam. The smalled thickness of the film is.. (0.10 micrometers)

C) Unpolarized light of intensity Io passes through a pair of polarizing filters with their axes making an angle of 38 degrees. What fraction of Io passes through? (0.31)

Let be a cylindrical box with a volume of 1200cm^3 and a weight of 0.13kg. 

-What is the maximum mass of lead that we can put in the box without it being submerged in water? 
 
The density of lead is 11.4 t/m3.

Can you comment how is it incomplete, What is missing?

A purple beam is hinged to a wall to hold up a blue sign. The beam has a mass of mb = 6.7 kg and the sign has a mass of ms = 17.4 kg. The length of the beam is L = 2.83 m. The sign is attached at the very end of the beam, but the horizontal wire holding up the beam is attached 2/3 of the way to the end of the beam. The angle the wire makes with the beam is θ = 34.5°.

1)What is the tension in the wire?

2)What is the net force the hinge exerts on the beam?

3)The maximum tension the wire can have without breaking is T = 946 N. What is the maximum mass sign that can be hung from the beam?

Two charges are placed on the x axis. One of the charges (q1 = +7.73C) is at x1 = +3.00 cm and the other (q2 = -23.7C) is at x2 = +9.00 cm. Find the net electric field (magnitude and direction given as a plus or minus sign) at (a) x = 0 cm and (b) x = +6.00 cm.

An electric ceiling fan is rotating about a fixed axis with an initial angular velocity magnitude of 0.200 rev/s . The magnitude of the angular acceleration is 0.883 rev/s2 . Both the the angular velocity and angular accleration are directed counterclockwise. The electric ceiling fan blades form a circle of diameter 0.760 m .

Two particles are fixed on an x axis. Particle 1 of charge 51.4 μC is located at x = -22.8 cm; particle 2 of charge Q is located at x = 10.8 cm. Particle 3 of charge magnitude 20.8 μC is released from rest on the y axis at y = 22.8 cm. What is the value of Q if the initial acceleration of particle 3 is in the positive direction of (a) the x axis and (b) the y axis?