if debroglie wavelength of moving electron is decreased from 1 to 0.5 then calculate change in ke
Answers
Answer:
Explanation:
energy=kinetic energy+work function
implies,energy =kinetic energy
energy=E=hc/lamda [h=planks constant=6*10^-34
c=velocity of light=3*10^8]
change in energy=change in kinetic energy
e1-e2= chnge in kinetic energy
(hc)/lambda1-(hc)/lambda2=change in kinetic energy
hc[(1/0.5)-(1/1)]=KE
KE=6*10^-34*3*10^8[0.5/0.5]
KE=18*10^-26
s = u t + ½ a t² ———————————-(1)
The body covers 20 m in 2s and 80 m in 4 s.
20 = u×2 + ½ a 2²; => 20 = 2 u + 2 a
u + a = 10 —————————————(2)
80 = u×4 + ½ a 4²; => 80 = 4 u + 8 a; this gives,
u + 2 a = 20 ——————————————(3)
Solving (2) and (3) for u and a we get
u = 0 m/s and a = 10 m/s² ————————(4)
To obtain the distance covered in the next 4s we need to find the velocity at the beginning of this interval using,
v = u + a t => v = 0 m/s + 1...
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RELATED QUESTIONS (MORE ANSWERS BELOW)
How many platinum atoms in a gram?
2 Answers
Pete Gannett, Associate Dean Research & Graduate Education at Nova Southeastern University (2015-present)
Answered Dec 5, 2017 · Author has 2.3k answers and 3manswer views
Well, you need to know the atomic weight of Platinum (Pt) and the number of atoms per mole. The answer to the former is 195.084 g/mole and the latter is 6.023 * 10^23 atoms/mole. Then, multiply everything as shown below:
Number of atoms = (1 g) * (1/195.084 g/mole) * 6.023 * 10^23 atoms/mole
Number of atoms = 3.087 * 10^21 atoms
Note, I’ve included units on everything and you can see that they all cancel except for atoms. Dragging the units along can be a pain but it is a great way to check that they way the numbers are being combined is correct.
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RELATED QUESTIONS (MORE ANSWERS BELOW)
How many platinum atoms in a gram?
2 Answers
Pete Gannett, Associate Dean Research & Graduate Education at Nova Southeastern University (2015-present)
Answered Dec 5, 2017 · Author has 2.3k answers and 3manswer views
Well, you need to know the atomic weight of Platinum (Pt) and the number of atoms per mole. The answer to the former is 195.084 g/mole and the latter is 6.023 * 10^23 atoms/mole. Then, multiply everything as shown below:
Number of atoms = (1 g) * (1/195.084 g/mole) * 6.023 * 10^23 atoms/mole
Number of atoms = 3.087 * 10^21 atoms