(10%) Problem 5: An alpha particle (a helium nucleus consisting of two protons a

Question

(10%) Problem 5: An alpha particle (a helium nucleus consisting of two protons and two neutrons) has a radius of approximately 1.6 x 10-15 m. A certain heavy nucleus contains 78 protons in addition to all its neutrons and has a radius of approximately 5.8 x 10-13 m. An alpha particle is shot directly from a large distance at such a resting heavy nucleus. Assuming that the heavy nucleus remains at rest d the ensuing process. w at initial kinetic energy, in Joules must the alpha particle n have in order to just reach the surface of the heavy nucleus Grade Summarv Deductions Potential 0% 100% Submissions Attempts remaining: 10 (090 per attempt) detailed view sin0 cos0 cotan asinacos0 atan acotan sinh0 cosh)tanhcotanh(O END Degrees Radians DEL? CLEAR Submit Hint I give up! Hints: 2% deduction per hint. Hints remaining: 4 Feedback: 1% deduction per feedback.

Explanation / Answer

r = distance between the center of two nucleus when closest = ralpha + rnucleus = 1.6 x 10-15 + 5.8 x 10-15 = 7.4 x 10-15

Qalpha = charge on alpha particle = 2 x 1.6 x 10-19 C
Qnucleus  = charge on nucleus = 78 x 1.6 x 10-19 C

Using conservation of energy:-

Kinetic energy = electric potential energy

KE = k Qalpha Qnucleus /r

KE = (9 x 109) (2 x 1.6 x 10-19 ) (78 x 1.6 x 10-19)/(7.4 x 10-15 ) = 4.85 x 10-12 J

Related Questions

Navigate

• Browse (All)
• Browse #
• Subjects

---

---

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