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Solar System

Calculate the Current Flowing through a Wire

A straight 1.77 mm diameter copper wire can just "float" horizontally in air because of the force of the Earth's magnetic field B which is horizontal and of magnitude 5.86E-5 T. What current does the wire carry? Please explain and solve problem.

Electromagnetism: Magnetic Force on Wire Carrying Current

Part 1 A high-voltage power line carries a current of 120 A at a location where the Earth's magnetic field has a magnitude of 0.583 G and points to the north, 70.8° below the horizontal. Calculate the magnitude of the magnetic force exerted on a 258 m length of wire if the current in the wire flows horizontally toward the ea

Vertical Electric field near earth's surface

See attached file. Full solution please No skipped steps. Answer is provided. This link will provide all notes needed for this problem: hide problem

Its about time - a discussion of time's nature

Before humans can seriously travel in time, that is extensively backward and forward, we need to first figure out what exactly "time" is. Anyone has a suggestive explanation on what "time is"? Please use at least one suitable site to support the answer (please don't use Wikpedia) Please provide the website(s) you use.

Astronomy: Light From Continuous Spectrum

1. Light from a source having a continuous Spectrum shines on a mass of Hydrogen gas. What sort of spectrum would you see if you were (a) on the opposite side of the gas from the source ? (b) off to the side ? Explain. 2. Two stars have the same temperature, but the absorption lines of one are narrower than the absorption lin

Astronomy Solar System Scales

1. If the Solar System were 10cm across, how big would the Milky Way galaxy be on that scale? Use the orbit of Neptune as the outer edge of the Solar System.


1. The phase of the Moon when it is aligned with the Sun in the sky is called the _____ Moon. Full Last Quarter First Quarter New 2. The phase of the Moon when it is located 180 degrees from the Sun is called the _____ Moon. Full Last Quarter First Quarter New 3. The phase of the Moon when

Celestial Sphere Problems

Question 1 What is the name of the point in space where the Sun appears to cross the celestial equator from South to North? __________ __________ Question 2 On what date does the Sun appear to cross the point on the celestial equator in Question 1? Question 3 What are the Sun's right ascension and declinati

Earth and Moon

1. If the axis of the Earth were tilted at 50 instead of 23.5, would the Summers in Europe be longer and hotter ? Explain. 2. Why do we always see the same face of the Moon from the Earth? 3. If a lunar eclipse occurs in January, can it be seen from the South Pole? Explain.

Physics: Maximum Range of a Projectile

A projectile being fired upward at an angle to the horizontal, θ. You are to program the spreadsheet Excel (a similar substitute software program is permissible) to determine the maximum injection angle, θmax , that will result in the greatest downrange distance, R. Assume vo = 10 m/s and g is approximated as g = 10

Physics: Currents and Magnetic Fields

Please help with the following physics problems. 1. The current that flows through an incandescent light bulb immediately after it is turned on is higher than the current that flows moments later. Why? 2. The Earth's magnetic field lines are not parallel to its surface except in certain places. They actually "dip" downwar

Perfect spring, spider silk, pendulum, energy of climber

For a "perfect" spring, the force applied to the spring as a function of amount of stretch is shown below. The work done is the area under the curve. Show that for an amount of stretch x, the work done is: W =1/2kx^2 The easiest way is to use the diagram and the relation F = kx. (Note: you have seen the equation F

Incompressible flow around a cylinder

Verify that the potential Phi = U (r +a^2/r)*cos(theta)-2U*a*theta can represent such a flow about a solid cylinder of radius a. Find the tangential velocity at the surface of the cylinder. Use Bernoulli's equation to show that the pressure field is given by: p(a,theta) = C - 2*rho*U^2*(sin^2 theta + 2sin theta) Fin

Coriollis Force and Noninertial Frames

A particle is projected vertically upward from the surface of the earth at colatitude (polar angle) theta. It rises to a height (h << R_earth) and then falls back to the surface. Show that it strikes the ground at a distance (8/3)*omega*sin(theta)*Sqrt(2h^3/g) to the west of the initial position, where omega = angular velocit

Magnetic field due to a current carrying wire

Jumper cables used to start a stalled vehicle often carry a 15 A current. How strong is the magnetic field 16 cm away? What percentage of the Earth's magnetic field (5.00 E-5 T) is this?

This job accounts for weightless feelings.

A bungee jumper feels weightless as she falls toward the Earth. Obviously the force of gravity has not disappeared simply because she has jumped off a high platform. What accounts for the weightless feeling people get when they fall freely?

Four problems on mechanics

Please help with the following problems. 1. A car starts from rest and reaches a speed of 31m/s in 2 seconds. Calculate its acceleration, if this value stays the same then what it the speed 7 seconds later? 2. A ball is thrown off a very tall building with a velocity of 16 m/s. What is the speed of the ball after 1.1 seco

Haley's comet orbits the sun every 76 years, and was first observed in 240bce.

Haley's comet orbits the sun every 76 years, and was first observed in 240bce. Its orbit is highly elliptical, so that its closest approach to the sun (perihelion) is only 0.587 AU, while at its greatest distance (aphelion), the comet is 34.39 AU from the sun. (An AU, or astronomical unit, is the distance from earth to the sun,

Astronomy is the most ancient science.

Astronomy is the most ancient science. Discuss how the development of astronomy is interrelated with the development of civilization. Some possible relationships include astrology, the names of constellations, calendars, and the basic ideas of mankind's place in the universe.

right ascension and declination of the point in the sky

Question 1 What are the right ascension and declination of the point in the sky where the ecliptic and the celestial equator intersect in March each year? The Sun crosses this point from the Southern Hemisphere to Northern Hemisphere in the sky. R.A. = _____ H _____ M Declination = __________ degrees __________ minut

Displacement Vector

See the attached file. Could you please provide the answers and workings out to the following physics problems. 8. which one of the following quantities is a vector quantity? a) the age of the earth b) the mass of a football c) the earth's pull on your body d) the temperature of an iron bar e) the number of people atte

Force of Mutual Attraction

Consider 2 iron spheres, each with a Diameter of 100mm which are just touching. a) Compute the force of mutual attraction when the spheres are just touching b) At what distance ,r, from the center of the earth will the force of mutual attraction between the contacting spheres be equal to the force exerted by the earth on

Potential Energies

Explain in everyday English and using formulas, the difference between 'electric potential' and 'electric potential energy'. Also explain, in the practical sense, why it matters that there is a difference. In other words, when will I ever see it? Also, explain why sometimes 'electrical' is interchanged with 'electrostatic' fo

The Net Gravitational Force on the Moon

The drawing (not to scale) shows one alignment of the sun, earth, and moon. The gravitational force FSM that the sun exerts on the moon is perpendicular to the force FEM that the earth exerts on the moon. The masses are: mass of the sun = 1.99 1030 kg, the mass of earth = 5.98 * 10^24 kg, mass of moon = 7.35 * 10^22 kg. The dis


12. The Universe according to the prevailing current body of evidence is likely to a. contract someday and implode on itself b. be an oscillator and right now it is simply in an expansion phase c. continue to expand forever d. heat up as the distance between galaxies increases 13.Select

Lorentz Force on an air plane due to earth magnetic field

Due to friction with the air, an airplane has acquired a net charge of 1.70 x 10^-5 C. The plane moves with a speed of 2.80 x 10^2 m/s at an angle with respect to the earth's magnetic field, the magnitude of which is 5.00 x 10^-5 T. The magnetic force on the airplane has a magnitude of 2.30 x 10^-7 N. What is the angle?

Modern Physics: Number of Cycles from Two Clocks

See attached file for full problem description. In the twin paradox, twin A remains on Earth while twin B travels a distance L, measured in the Earth's inertial frame, at a velocity v to a very distant solar system. In turning around for the return trip, the rocket malfunctions somewhat and achieves only a velocity ½ v. Fi