For Potassium Metal, the Work Function $\phi$ (The Minimum Energy Needed to Eject an Electron from the Needed

question 29

Multiple Choice

For potassium metal, the work function $\phi$ (the minimum energy needed to eject an electron from the metal surface) is 3.68 * 10¯¹⁹ J. Which is the longest wavelength of the following which could excite photoelectrons?

• A) 550. nm
• B) 500. nm
• C) 450. nm
• D) 400. nm
• E) 350. nm

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Definitions:

Isotonic Contraction

A type of muscle contraction in which the muscle changes length while the tension remains constant, typically involved in lifting and moving objects.

Isometric Contraction

Muscle contraction that occurs without changes in muscle length, resulting in tension without movement.

Concentric Tension

Refers to the force generated by muscle fibers shortening during contraction, often used in the context of exercise and muscle physiology.

Inner Ear

The innermost part of the ear, responsible for hearing and balance, containing the cochlea, vestibule, and semicircular canals.