Author Question: An electron moving perpendicular to a uniform magnetic field of 0.22 T moves in a circle with a ... (Read 77 times)

imanialler

  • Hero Member
  • *****
  • Posts: 539
An electron moving perpendicular to a uniform magnetic field of 0.22 T moves in a circle with a speed of 1.5  107 m/s. What is the radius of the circle? (e = 1.60  10-19 C, melectron = 9.11  10-31kg)
 
  A) 1.5 mm
  B) 0.22 mm
  C) 2.2 mm
  D) 0.39 mm
  E) 3.9 mm

Question 2

When light of wavelength 350 nm is incident on a metal surface, the stopping potential of the photoelectrons is 0.500 V.
 
  What is the threshold (cutoff) frequency of this metal? (c = 3.00  108 m/s, h = 6.626  10-34 J  s, 1 eV = 1.60  10-19 J)
  A) 3.47  1014 Hz
  B) 3.74  1014 Hz
  C) 4.73  1014 Hz
  D) 7.36  1014 Hz


cpetit11

  • Sr. Member
  • ****
  • Posts: 321
Answer to Question 1

E

Answer to Question 2

D



Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
 

Did you know?

For about 100 years, scientists thought that peptic ulcers were caused by stress, spicy food, and alcohol. Later, researchers added stomach acid to the list of causes and began treating ulcers with antacids. Now it is known that peptic ulcers are predominantly caused by Helicobacter pylori, a spiral-shaped bacterium that normally exist in the stomach.

Did you know?

As of mid-2016, 18.2 million people were receiving advanced retroviral therapy (ART) worldwide. This represents between 43–50% of the 34–39.8 million people living with HIV.

Did you know?

Pink eye is a term that refers to conjunctivitis, which is inflammation of the thin, clear membrane (conjunctiva) over the white part of the eye (sclera). It may be triggered by a virus, bacteria, or foreign body in the eye. Antibiotic eye drops alleviate bacterial conjunctivitis, and antihistamine allergy pills or eye drops help control allergic conjunctivitis symptoms.

Did you know?

Chronic necrotizing aspergillosis has a slowly progressive process that, unlike invasive aspergillosis, does not spread to other organ systems or the blood vessels. It most often affects middle-aged and elderly individuals, spreading to surrounding tissue in the lungs. The disease often does not respond to conventionally successful treatments, and requires individualized therapies in order to keep it from becoming life-threatening.

Did you know?

About 100 new prescription or over-the-counter drugs come into the U.S. market every year.

For a complete list of videos, visit our video library