Let's say you want to produce a (roughly) uniform electric field using a very large nonconducting sheet. However, you still want to be able to access the regions above and below the sheet, so a drill a small hole with a radius of 1.80 cm into the sheet. You can assume that very large means "infinite" in this context. The sheet has a surface charge density of 4.50 pC/m2. What is the magnitude of the electric field at a point 2.56 cm above the sheet after the hole is drilled into the sheet? You drill the hole such that the point we are considering lines directly above the center axis of the hole.

Hint: Remember that electric fields obey the superposition principle. What charge distribution can you add on top of the sheet to create the absence of charge (i.e., not net charge) in "hole" region?

A crate of mass 100.0 kg rests on a rough surface inclined at an angle of 37.0° with the horizontal. A massless rope to which a force can be applied parallel to the surface is attached to the crate and leads to the top of the incline. In its present state, the crate is just ready to slip and start to move down the plane. The coefficient of friction is 80% of that for the static case

a.    What is the coefficient of static friction?

b.    What is the maximum force that can be applied upward along the plane on the rope and not move the block?

c.     With a slightly greater applied force, the block will slide up the plane. Once it begins to move, what is its acceleration and what reduced force is necessary to keep it moving upward at constant speed?

d.    If the block is given a slight nudge to get it started down the plane, what will be its acceleration in that direction?

e.    Once the block begins to slide downward, what upward force on the rope is required to keep the block from accelerating downward?

1-state the relationship between a wave's velocity wavelength and frequency?

2- What is the principle of superposition?

3- The distance between two nodes or two antinodes in a standing wave is …………………. Wavelength?

4- - The distance between an antinode and a node in a standing wave is …………………. Wavelength?

5- A string, which has a mass of 0.50 kg and a length of 3.0 meters, is clamped on both ends. If the tension in the string is 25 Newtons, what are the lowest 3 natural frequencies of oscillation of the string? For each case, include a sketch of the standing wave pattern.

An RLC series circuit consists of a 450-Ω resistor, a 3.00-mF capacitor, and a 1.00-H inductor. The circuit is driven by a power source that oscillates at 20.0 Hz and has an Erms value of 30.0 V . The power source is switched on at t = 0 and at that instant the emf is at its maximum value.

Part A Calculate the power supplied at t = 0.0200 s.

Part B Calculate the power supplied at t = 0.0375 s.

Part C Calculate the power supplied at t = 0.0500 s.

a-How much heat is required to convert 5.0 kg of ice from a temperature of -10 C to water vapor at a temperature of 220F? b-You have 200 g of coffee at 55 C, Coffee has the same specific heat as water. How much ice at -5 C do you need to add in order to reduce the coffee’s temperature to 27C.

Having aced your introductory physics course, you are hired as a summer intern at NASA. You are sent as part of a team to explore the possibility of mining iron from a small, airless spherical asteroid with a radius of 469 km and a surface acceleration of 3.4 m/sec2.

4)How far will the 3 kg rock go if it leaves the asteroids surface with a vertical velocity of 1000 m/sec?"

(Not sure why the answer isn't 147059 m. I used vf^2 = vi^2 + 2ah. 0 = 1000^2 + 2 * -3.4 m/s * h. h = (1000^2) / (2*3.4) = 147059 m.)

5)What will the speed of the 6 kg rock be at the surface of the asteroid if it is dropped from a point 1000km above the surface of the asteroid?

(Not sure why the answer isn't 2608 m/s. I did v=sqrt(2ah) = sqrt(2*3.4*1000000).)

A 5.00-kg bullet moving with an initial speed of V_i= 400 m/s is fired into and passes through a 1.00-kg block as shown in the Figure. The block, initially at rest on a frictionless, horizontal surface, is connected to a spring with force constant 1000 N/m. The block moves d = 5.00 cm to the right after impact before being brought to rest by the spring. Find:

The speed at which the bullet emerges from the block.

The kinetic energy lost (the amount of intial kinetic energy of the bullet that is converted into internal energy, i.e. heat, in the bullet-block system) during the collison.

1. Compute the mechanical work done by the helicopter on lifting a 1,200-kg house to a

height of 800m. Show all your work.

2. What maximum speed (in miles per hour) can a 1,800-kg, 160-horse-power car theoretically develop moving up a 30-degree slope? Show all your work.

3. A boat of mass 720kg (including passengers) floats stationary on water before an 80-kg woman jumps into it horizontally at 5m/s. At what speed does the boat begin to move? Show all your work.

white printer paper have an equal mass, but unequal surface area

coffee filters have an equal surface area with unequal in mass

how does mass and surface area affect the free fall of an object? do theses qualities affect the pull of gravity or resistance of the air?

connect the paper and coffee filters object to 1st, 2nd newton law and friction

A railroad car of mass 2.20 ✕ 10⁴ kg moving at 5.00 m/s collides and couples with two coupled railroad cars, each of the same mass as the single car and moving in the same direction at 1.20 m/s.

(a) What is the speed of the three coupled cars after the collision?
  _________________m/s
(b) How much kinetic energy is lost in the collision?
  ________________J

The normalized wave function of an electron in a linear accelerator is ψ = (cos χ)e^ikx + (sin χ)e^–ikx, where χ (chi) is a parameter. (a) What is the probability that the electron will be found with a linear momentum (a) +kħ, (b) −kħ? (c) What form would the wave function have if it were 90% certain that the electron had linear momentum +kħ? (d) Evaluate the kinetic energy of the electron.

Bart and Nelson challenged each other to a bumper car game. Bart, whose car had a mass of 120 kg (with him in it), traveled west at a velocity of 9 m/s. Nelson and his car had a total mass of 150 kg traveled a velocity of 7 m/s east, heading towards Bart. The two had a head-on collision. Use the frame of reference in which the east is positive.

a) If Bart left the collision at a velocity of 7 m/s east, what velocity did Nelson leave with?

b) Determine the total kinetic energy for Bart and Nelson before the collision. Determine the total kinetic energy after the collision.

c) Instead of heading towards each other, Bart was going 9 m/s east following behind Nelson, whose velocity is still 7 m/s east. At what velocity would Bart travel at after the collision if Nelson left the collision with a velocity of 7 m/s east?

Show how the wave function of the even states of a particle in an infinite well extending from x=-L/2 to x=L/2 evolve in time. Details!

5) A solenoid passes through the x-y plane. A charge of +5 Coulombs with a mass of 5 x 10-7 kg moving at 5 m/s (in the x-y plane) is placed in the solenoid. Due to the magnetic field produced by the solenoid, the charge moves counter-clockwise in a circle at a frequency of 34 Hz. The charge is removed and a circular wire wound 3 times with a radius of 0.6 meters is placed in the solenoid. If the total magnetic field at the center of the circular is zero, what is the amount and direction of the current in the circular wire in amps? Indicate clockwise by a negative sign (negative answer) and don't enter a sign for counter-clockwise.

4. Ammeter: Explain how to setup a DMM to measure current in the circuit. Will it matter if the ammeter (DMM used to measure current) is before or after the resistor (on the side of the + or – terminal)?.