VJC

Popular questions and responses by VJC
  1. physics

    An electron starting from rest acquires 4.20 keV of kinetic energy in moving from point A to point B. How much kinetic energy would a proton acquire, starting from rest at B and moving to point A? Determine the ratio of their speeds at the end of their

    asked on September 8, 2010
  2. College Physics II

    A typical gamma ray emitted from a nucleus during radioactive decay may have an energy of 736 keV. What is its wavelength? A microwave oven produces electromagnetic radiation at λ = 12.1 cm and produces a power of 778 W. Calculate the number of microwave

    asked on November 25, 2010
  3. physics

    On planet Tehar, the acceleration of gravity is the same as that on Earth but there is also a strong downward electric field with the field being uniform close to the planet's surface. A 2.16 kg ball having a charge of 4.80 uC is thrown upward at a speed

    asked on September 8, 2010
  4. College Physics II

    1) An electron moving with a speed of 2.84E+6 m/s has the same momentum as a photon. Calculate the de Broglie wavelength of the electron. 2) Calculate the wavelength of the photon.

    asked on November 25, 2010
  5. physics

    A high-voltage power line carries a current of 120 A at a location where the Earth's magnetic field has a magnitude of 0.577 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

    asked on October 11, 2010
  6. Physics

    Suppose a spacecraft of rest mass 34000 kg is accelerated to 0.206c. How much kinetic energy would it have? If you used the classical formula for KE, by what percentage would you be in error? Do not enter units.

    asked on November 21, 2010
  7. Physics

    Calculate the magnitude of the electric field at the center of a square with sides 22.4 cm long if the corners, taken in rotation, have charges of 1.02 μC, 2.04 μC, 3.06 μC, and 4.08 μC (all positive).

    asked on September 8, 2010
  8. College Physics II

    What is the longest wavelength light capable of ionizing a hydrogen atom in the n = 4 state? i know that Solve h c/L = (Rydberg)/6^2 for L something along those lines... but what am i solving for and what is c and h?

    asked on December 8, 2010
  9. physics

    How much work is needed to move a proton from a point with a potential of +470 V to a point where it is -51.0 V? Express your answer in joules. Express your answer in electron volts.

    asked on September 15, 2010
  10. physics

    A 5.30 cm diameter wire coil is initially oriented so that its plane is perpendicular to a magnetic field of 0.570 T pointing up. During the course of 0.190 s, the field is changed to one of 0.350 T pointing down. What is the average induced emf in the

    asked on October 18, 2010
  11. physics

    The force on a wire is a maximum of 7.33E-2 N when placed between the pole faces of a magnet. The current flows horizontally to the right and the magnetic field is vertical. The wire is observed to "jump" toward the observer when the current is turned on.

    asked on October 11, 2010
  12. physics

    An emf is induced in a conducting loop of wire 1.24 m long as its shape is changed from square to circular. Calculate the average magnitude of the induced emf if the change in shape occurs in 4.21 s, and the local 0.123 T magnetic field is perpendicular to

    asked on October 18, 2010
  13. physics

    An electric field of 630 V/m is desired between two parallel plates 15.9 mm apart. How large a voltage should be applied?

    asked on September 8, 2010
  14. physics

    A 34.7 cm diameter coil consists of 20 turns of circular copper wire 1.50 mm in diameter. A uniform magnetic field, perpendicular to the plane of the coil, changes at a rate of 9.00E-3 T/s. Determine the current in the loop. Determine the rate at which

    asked on October 18, 2010
  15. Physics

    At a certain location, the Earth's magnetic field has a magnitude of 5.90E-5 T and points in a direction that is 71.6° below the horizontal. Calculate the magnitude of the magnetic flux through the top of a desk at this location that measures 132 cm by

    asked on October 18, 2010
  16. Physics

    What is the speed of a 680 eV electron? What is the speed of a 3.50 keV electron?

    asked on September 8, 2010
  17. physics

    A proton with a kinetic energy of 5.00E-16 J moves perpendicular to a magnetic field of 0.289 T. What is the radius of its circular path?

    asked on October 11, 2010
  18. physics

    Two parallel plates, separated by 10 mm, are charged to a potential difference of 50 V (that is, one plate is 0 V and the other plate is 50 V). Which of the following statements are true? the electric potential at the midpoint between the plates is 50 V

    asked on September 13, 2010
  19. physics

    An object has a total energy that is two times its rest energy. What is its speed? Give answer in c. what equation do i use to solve this? step by step anyone?

    asked on November 17, 2010
  20. College Physics II

    A uniform electric field of magnitude 203 V/m is directed in the negative y direction. A +12.5 μC charge moves from the origin to the point (x, y) = (19.5 cm, 51.8 cm). 1) What was the change in the potential energy of this charge? 2) Through what

    asked on September 15, 2010
  21. Physics

    A uniform electric field of magnitude 203 V/m is directed in the negative y direction. A +12.5 μC charge moves from the origin to the point (x, y) = (19.5 cm, 51.8 cm). 1) What was the change in the potential energy of this charge? 2) Through what

    asked on September 8, 2010
  22. Physics

    A 17.0 cm diameter circular loop of wire is in a 1.35 T magnetic field. It is removed from the field in 0.190 s. What is the average induced emf?

    asked on October 18, 2010
  23. College Physics II

    Consider a region in space where a uniform electric field E = 7450 N/C points in the negative x direction. What is the distance between the +13.1 V and the +14.1 V equipotentials?

    asked on September 15, 2010
  24. College Physics II

    A charge of -4.191 μC is located at (5.100 m, 6.402 m), and a charge of 1.895 μC is located at (-1.436 m, 0). Calculate the electric potential at the origin There is one point on the line connecting these two charges where the potential is zero. What is

    asked on September 15, 2010
  25. College Physics II

    If a capacitor has 3.84 μC of charge on it and an electric field of 2.22 kV/mm is desired if they are separated by 3.80 mm of air, what must each plate's area be?

    asked on September 15, 2010
  26. physics

    Protons move in a circle of radius 4.10 cm in a 0.570 T magnetic field. What value of electric field could make their paths straight?

    asked on October 11, 2010
  27. College Physics II

    What is the de Broglie wavelength of electrons with the following value of kinetic energy? 1.06 eV; What is the de Broglie wavelength of electrons with the following value of kinetic energy? 1.06 keV.

    asked on November 25, 2010
  1. College Physics II

    so i would do speed of light/(rydberg)/6^2=h?

    posted on December 8, 2010
  2. Atomic physics

    what is h and c?

    posted on December 8, 2010
  3. Physics

    what would happen if it became 1/4 the total energy instead? how would the equation be set up?

    posted on November 17, 2010
  4. physics

    what is H?

    posted on September 15, 2010