Answer:
h f = W + KE
Input energy equals work function plus KE of emitted electron
W = 6.63E-34 * 2.5E15 - 6.3 * 1.6E-19
W = 6.63 * 2.5 * 10^-19 - 10.1 * E-19 ev (1ev = 1.6E-19 J)
W = (16.6 - 10.1)E-19 = 6.5E-19 J
h f = 6.5E-19 J for electrons to be emitted with zero KE
f = 6.5E-19 / 6.63E-34 = .98E-15 / sec = 9.8E-14 / sec (threshold)
The most important mineral resources of Virginia are coal, crushed stone, sand and gravel, lime (from limestone and dolostone) and natural gas.
C. located in front of the lens
Answer:
We will use Potential Energy Formula
Potential Energy = mass × gravitation × height
PE = 0,55 × 10 × 4
PE = 22 J (A)
