Why can’t the human body sense magnetic fields in our bodies when neurons “fire”

1 For the following questions consider a compound of calcium and chlorine.

a What type of bond do calcium and chlorine form?

b Describe how this bond forms.

c What is the chemical formula for the compound? Explain.

2 For the following questions consider a water molecule, H₂O.

a What type of bond is formed between the oxygen and the hydrogen atoms?

b Describe how these bonds form.

c Explain why there are two hydrogen atoms for each oxygen atom.

3 For the following questions consider a piece of copper wire.

a What type of bond is formed between the copper atoms?

b Describe how these bonds form.

c Explain why copper is a good electrical conductor.

Why do astronomers think there are two basically different types of gamma-ray burst?

A tube at room temperature which is 0.680 m long is open on both ends. Which frequencies of sound will resonate in the tube?

The tube is then covered on one end. Which frequencies of sound will resonate in the tube now?

e) lowest frequency


f) 2nd lowest frequency

g) 3rd lowest frequency

h) What is the highest frequency of audible sound that will resonate in this tube?

1.A 15 pF capacitor is charged to 1 kV and
then removed from the battery and connected
in parallel to an uncharged 65 pF capacitor.
What is the new charge on the second ca-
pacitor?
Answer in units of nC

2.What is the new charge on

3.Find the change in energy.
Answer in units of ?J

You plan to take a trip to the moon. Since you do not have a traditional spaceship with rockets, you will need to leave the earth with enough speed to make it to the moon. Some information that will help during this problem:

mearth = 5.9742 x 1024 kg

rearth = 6.3781 x 106 m

mmoon = 7.36 x 1022 kg

rmoon = 1.7374 x 106 m

dearth to moon = 3.844 x 108 m (center to center)

G = 6.67428 x 10-11 N-m2/kg2

1) On your first attempt you leave the surface of the earth at v = 5534 m/s. How far from the center of the earth will you get?

2) Since that is not far enough, you consult a friend who calculates (correctly) the minimum speed needed as vmin = 11068 m/s. If you leave the surface of the earth at this speed, how fast will you be moving at the surface of the moon? Hint carefully write out an expression for the potential and kinetic energy of the ship on the surface of earth, and on the surface of moon. Be sure to include the gravitational potential energy of the earth even when the ship is at the surface of the moon!

(Please inlude step-by-step solution or even an online video link that can teach me this as well)

A wave in a string has a wave function given by: y (x, t) = (0.0300m) sin [(5.35 m^-1) x + (1.63 s^-1) t]
  where t is expressed in seconds and x in meters. Determine:

a) the amplitude of the wave
b) the frequency of the wave
c) wavelength of the wave
d) the speed of the wave

A 5.00-MΩ Ω resistor and a 5.00-μ μ F capacitor are connected in series with a power supply. 1) What is the time constant for the circuit

Part B A 20.0-μ μ F capacitor has an initial charge of 100.0 μ μ C. 1) If a resistance of 20.0 Ω Ω is connected across it, what is the initial current through the resistor?

Part C A 12.5-μ μ F capacitor is charged to a potential of 30.0 V and then discharged through a 65.0­ Ω Ω resistor. 1) How long after discharge begins does it take for the capacitor to lose 90.0% of its initial charge? (Express your answer to three significant figures.) ms m s 2) How long after discharge begins does it take for the capacitor to lose 90.0% of its initial energy? (Express your answer to three significant figures.) ms m s 3) What is the current through the resistor at the time when the capacitor has lost 90.0% of its initial charge? (Express your answer to three significant figures.) mA m A 4) What is the current through the resistor at the time when the capacitor has lost 90.0% of its initial energy? (Express your answer to three significant figures.) mA

The Doppler effect - the shift in frequency/wavelength of a sound source when there is relative motion between source & observer - and a Sonic Boom - a conical region of compression that forms around the sound source when its speed exceeds the speed of sound in the medium of the source, and results in an observed "boom" when part of the cone passes the observer's location - are two interesting, common, as well as connected phenomena seen this week.

For the Doppler effect, give and discuss briefly two applications, see if you can do one stemming from nature and one technology (man-made).

For the sonic boom, see if you can give two occurrences stemming from nature and two from man-made situations.

Please no handwritten or picture respones - only typed replies.

With axle and spokes of negligible mass and a thin rim, a certain bicycle wheel has a radius of 0.350 m and weighs 33.0 N; it can turn on its axle with negligible friction. A man holds the wheel above his head with the axle vertical while he stands on a turntable that is free to rotate without friction; the wheel rotates clockwise, as seen from above, with an angular speed of 66.0 rad/s, and the turntable is initially at rest. The rotational inertia of wheel + man + turntable about the common axis of rotation is 2.00 kg·m2. The man's free hand suddenly stops the rotation of the wheel (relative to the turntable). (a) Determine the resulting angular speed of the system. (b) Is the direction of the rotation clockwise or counterclockwise?

Consider the projectile motion of two balls. Ball A is launched horizontally (no vertical component of velocity) with an initial speed of 100 m/s from an initial position 1 m above the ground. Ball B is launched straight upward (no horizontal component of velocity) with an initial speed of 1 m/s from an initial position 0.5 m above the ground. The two balls are launched at the same time. Assume that air resistance doesn’t matter in this problem and assume the ground is perfectly flat.

a) What is the horizontal component of velocity for each ball when they hit the ground?

b) What is the vertical position of ball B when it reaches its maximum height?

c) What time does ball B reach its maximum height? d) Which ball reaches the ground first?

A 1.1 kg mass is held at rest on top of a frictionless and horizontal table. A light string loops over a pulley which is in the shape of a 10 cm radius solid disk which has a mass of 1.1 kg. The light string then supports a mass of 1.1 kg which is hanging in air.

The mass on the table is released and the suspended mass falls. What is the acceleration of the falling mass.

What is the tension in the string which is attached to the sliding mass on the table?

What is the tension of the string which supports the hanging mass?

Sprinter Usain Bolt reached a maximum speed of 11.2 m/s in 2.0s while running 100-m dash. A) what was his acceleration? B) What distance did he travel during his first 2.0s of the race? C) What assumptions did you make? D) What time interval was needed to complete the race assuming that he ran the last part of the race at his maximum speed? E) what is the total time of the race? How certain are you of the number you calculated?

*****Show all work*******

Considering the Electro Magnetic Flow Meter application of electromagnetism. Discuss its operation principle, theoretical background and future developments

Consider a dense electron gas in a given metal. What is the characteristic temperature? What does this mean physically?