three charges are placed on the corners of an equilateral triangle with side lenght L. calculate the force on the bootom right charge. Record your answer as a vector in i,j,k. your answer should be in term of k,L and Q

Two lasers are shining on a double slit, with slit separation d. Laser 1 has a wavelength of d/20, whereas laser 2 has a wavelength of d/15. The lasers produce separate interference patterns on a screen a distance 5.30m away from the slits.

1.Which laser has its first maximum closer to the central maximum? Laser one or Laser 2 ?

2. What is the distance ?ymax?max between the first maxima (on the same side of the central maximum) of the two patterns? Answer in m

3.What is the distance ?ymax?min between the second maximum of laser 1 and the third minimum of laser 2, on the same side of the central maximum?

Please show work, and units.

Imagine cart 1 with initial velocity v1i collides with cart 2 with initial velocity v2i = 0, where they then move together as a single mass (attached by velcro). Sketch the expected center of mass position over time graph. Assume t = 0 corresponds to the moment immediately after the impulse to cart 1 is delivered and assume equal masses (m1 = m2). Ignoring the effects of friction, is the above collision elastic or inelastic? Why?

harmonic if the period (the time for one cycle) does not depend on the amplitude (the maximum displacement from equilibrium). In the following set, identify the oscillations that are simple harmonic, the ones that are approximately simple harmonic, and the ones that are not simple harmonic. Please comment on why/how you make your identifications.

1. The pendulum in a grandfather clock

2. A boat in water pushed down and released

3. A child on a swing

4. A mass hanging from a spring

5. A ping pong ball bouncing on the floor.

A proton in a high-energy accelerator moves with a speed of c/2. Use the work

1. Did the values of μ measured directly and indirectly agree?

2. As the tension is increased, does the number of segments increase or decrease when the frequency is kept constant?

3. As the frequency is increased, does the number of segments increase or decrease when the tension is kept constant?

4. As the tension is increased, does the speed of the wave increase, decrease, or stay the same when the frequency is kept constant?

5. As the frequency is increased, does the speed of the wave increase, decrease, or stay the same when the tension is kept constant?

6. Suppose that String #1 is twice as dense as String #2, but both have the same tension and the same length. If each of the strings is vibrating in the fundamental mode, which string will have the higher frequency?

Two blocks are positioned on surfaces, each inclined at the same angle 45.6 degrees with respect to the horizontal. The blocks are connected by a rope which rests on a frictionless pulley at the top of the inclines, so the blocks can slide together. The mass of the black block is 4.10kg and the coefficient of kinetic friction for both blocks and inclines is μk 0.370. Assume static friction has been overcome and that everything can slide. A) What must be the mass of the white block if both blocks are to slide to the right at a constant velocity? B)What must be the mass of the white block if both blocks are to slide to the left at a constant velocity? C) What must be the mass of the white block if both blocks are to slide to the right at an acceleration of 1.5m/s^2? D) What is must be the mass of the white block if both blocks are to slide to the left at an acceleration of 1.5 m/s2? E)Now, re-do part (d) above, but now assuming no friction at all on either incline. So in the absence of friction, what must be the mass of the white block such that both blocks slide to the left at an acceleration of 1.5 m/s2?

(a) Keck-I has a 10m diameter mirror. HST (Hubble Space Telescope) has a 2.4m mirror.

What is the ratio of the light gathering power of Keck-I to the light-gathering power of HST?

[Compute the ratio (light gathering power of Keck)/(light gathering power of HST) and express as a decimal. Do not use scientific notation.]

(b) What is the ratio of the angular resolution limit of Keck to the angular resolution limit of HST? (Assume they are both observing at the same wavelength.)

[Compute the relevant ratio Keck/HST, express as a decimal, and enter below.]

(c) HST orbits at an altitude of 559 km above the Earth's surface. Assume its orbit is circular.

Compute its orbital period in hours.

(d) Compute its orbital speed (in km/s).

(e) If a satellite like Hubble was looking down at the Earth instead of up, what is the smallest physical size (in cm) on the Earth’s surface that it could resolve? [Hint: assume you are using the visible spectrum.]

The potential at the center of a uniformly charged ring is 44 kV , and 11 cm along the ring axis the potential is 31 kV .

Find the ring's radius.

Find the ring's total charge.

Which of these are actual evidence for the existence of a black hole in the center of the Milky Way, and which are not?

Stars are observed to disappear into the black hole

Bright quasar emission is detected from the center of the galaxy

Telescopes have been used to take high resolution images of the black hole's event horizon

Astronomers observe an extremely bright and compact radio source

The closest approach of stellar orbits near the center of the galaxy indicate the object is smaller than the solar system

Stellar velocities near the center of the galaxy indicate 4 million times the mass of the sun inside their orbit

Find all possible values of the following for a hydrogen atom in a 3d state.

I have the value of L as 2.57e-34 which is correct.

L_z. (Enter your answers from smallest to largest. Enter NONE in any unused answer blanks. Use the following as necessary: h(bar))

There are 4 boxes and the 2nd and 3rd are 1 and 2 but i cannot get the first and fourth boxes.

θ. (Enter your answers from smallest to largest. Enter NONE in any unused answer blanks.)

there are 8 boxes for this part.

Thank you!

A girl is sitting near the open window of a train that is moving at a velocity of 22.00 m/s to the east. The girl's uncle stands near the tracks and watches the train move away. The locomotive whistle emits sound at frequency 770.0 Hz. The air is still. (Use 343 m/s for the speed of sound in air for all parts of this question.) (a) What frequency does the uncle hear? Hz (b) What frequency does the girl hear? Hz (c) A wind begins to blow from the east at 22.00 m/s. What frequency does the uncle now hear? Hz (d) What frequency does the girl now hear? Hz

1. A 200 g aluminum calorimeter contains 500 g of water at 20 C. A 100 g piece of ice cooled to -20 C is placed in the calorimeter.

1. Find the final temperature of the system, assuming no heat losses. (The specific heat of ice is 2.0 kJ/kg K)
2. A second 200 g piece of ice at -20 C is added. How much ice remains in the system after it reaches equilibrium?
3. Would your answer to part b be different if both pieces of ice were added at the same time?

(specific heat of aluminum is 0.9 kJ/kg K and water is 4.18 kJ/kg K)

At takeoff a commercial jet has a 70.0 m/s speed. Its tires have a diameter of 0.400 m.

(a) At how many rpm are the tires rotating?
  rpm
(b) What is the centripetal acceleration at the edge of the tire?
  m/s²
(c) With what force must a determined 10^-15 kg bacterium cling to the rim?
N
(d) Take the ratio of this force to the bacterium's weight.
(force from part (c) / bacterium's weight)

(a) A 23.0 kg child is riding a playground merry-go-round that is rotating at 45.0 rpm. What centripetal force must she exert to stay on if she is 2.50 m from its center?
  N
(b) What centripetal force does she need to stay on an amusement park merry-go-round that rotates at 3.00 rpm if she is 5.00 m from its center?
  N
(c) Compare each force with her weight.
  (force from part (a) / weight)
  (force from part (b) / weight)

All of these answers wrong someone please help me.

Special relativity

Q: What is Einstein’s special relativity principle?

Q: What is the relativity of simultaneity?

Q: What is time dilation? Length contraction?

Q: Why is there a cosmic speed limit?