In Rutherford\'s famous scattering experiments that led to the planetary model o

Question

In Rutherford's famous scattering experiments that led to the planetary model of the atom, alpha particles (having charges of +2e and masses of 6.64 times 10^-27 kg) were fired toward a gold nucleus with charge +79e. An alpha particle, initially very far from the gold nucleus, is fired at 1.4 times 10^7 m/s directly toward the nucleus, in the figure below. How close does the alpha particle get to the gold nucleus before turning around? Assume the gold nucleus remains stationary. Rank the electric potentials at the four points shown in the figure below from largest to smallest. (Use only ">" symbols. Do not include any parenthesis around the letters or symbols.)

Explanation / Answer

ANSWER

From conservation of energy

KEi+PEi =KEf+PEf

0+KQq/r =(1/2)mVi^2 +0

=>r=2KQq/mVi^2

=>r=2*(9*10^9)(79*1.6*10^-19)(2*1.6*10^-19)/(6.64*10^-27)(1.4*10^7)^2

=>r=5.59*10^-14 m   ANS.

Regards!!!

Related Questions

Navigate

• Browse (All)
• Browse I
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.