An alpha particle (charge 2e) is aimed directly at a gold nucleus (charge 79e). What minimum initial kinetic energy must the alpha particle have to approach within 7.0 * 10-14 m of the center of the gold nucleus before reversing direction? Assume that the gold nucleus, which has about 40 times the mass of an alpha particle, remains at rest.

An alpha particle (charge 2e) is aimed directly at a gold nucleus (charge 79e). What minimum initial kinetic energy must the alpha particle have to approach within 7.0 * 10-14 m of the center of the gold nucleus before reversing direction? Assume that the gold nucleus, which has about 40 times the mass of an alpha particle, remains at rest.

Principles of Physics: A Calculus-Based Text

5th Edition

ISBN:9781133104261

Author:Raymond A. Serway, John W. Jewett

Publisher:Raymond A. Serway, John W. Jewett

Chapter29: Atomic Physics

Section: Chapter Questions

Problem 1P

See similar textbooks

Similar questions

If two nuclei are to fuse in a nuclear reaction, they must be moving fast enough so that the repulsive Coulomb force between them does not prevent them for getting within R1014mof one another. At this distance or nearer, the attractive nuclear force can overcome the Coulomb force, and the nuclei are able to fuse. (a) Find a simple formula that can be used to estimate the minimum kinetic energy the nuclei must have if they are to fuse. To keep the calculation simple, assume the two nuclei are identical and moving toward one another with the same speed v. (b) Use this minimum kinetic energy to estimate the minimum temperature a gas of the nuclei must have before a significant number of them will undergo fusion. Calculate this minimum temperature first for hydrogen and then for helium. (Hint: For fusion to occur, the minimum kinetic energy when the nuclei are far apart must be equal to the Coulomb potential energy when they are a distance R apart.)
(a) Show that if you assume the average nucleus is spherical with a radius r=r0A1/3, and with a mass at A u, then its density is independent at A. (b) Calculate that density in u/fm3 and kg/m3, and compare your results with those found in Example 31.1 for 56Fe.
This problem demonstrates that the binding energy of the electron in the ground state of a hydrogen atom is much smaller than the rest mass energies of the proton and electron. Calculate the mass equivalent in u of the 13.6-eV binding energy of an electron in a hydrogen atom, and compare this with the known mass of the hydrogen atom. Subtract the known mass of the proton from the known mass of the hydrogen atom. Take the ratio of the binding energy of the electron (13.6 eV) to the energy equivalent of the electron’s mass (0.511 MeV). Discuss how your answers confirm the stated purpose of this problem.
When a nucleus (decays, does the (particle move continuously from inside the nucleus to outside? That is, does it travel each point along an imaginary line from inside to out? Explain.
An alpha particle (charge +3.20 x 10^-19C, mass 6.64 x10^-27kg) is initially 5.2cm away from a fixed golden nucleus (charge +1.36 x10^-17C, mass 3.29x10^-25kg), and moving toward the nucleus with a speed of 8.1x10^5m/s. How close to the nucleus does te alpha particle get? Note: the nucleus diameter is approximately 10^-14m and the alpha particles's is 10^-15m
A beam of alpha particles is incident on a target of lead. A particular alpha particle comes in “head-on” to a particular lead nucleu and stops 6.50 * 10-14 m away from the center of the nucleus. (This point is well outside the nucleus.) Assume that the lead nucleus, which has 82 protons, remains at rest. The mass of the alpha particle is 6.64 * 10-27 kg. (a) Calculate the electrostatic potential energy at the instant that the alpha particle stops. Express your result in joules and in MeV. (b) What initial kinetic energy (in joules and in MeV) did the alpha particle have? (c) What was the initial speed of the alpha particle?
A solid copper sphere whose radius is 1.0 cm has a verythin surface coating of nickel. Some of the nickel atoms areradioactive, each atom emitting an electron as it decays. Halfof these electrons enter the copper sphere, each depositing 100 keVof energy there.The other half of the electrons escape, each carryingaway a charge e.The nickel coating has an activity of 3.70 *10^8 radioactivedecays per second. The sphere is hung from a long, nonconductingstring and isolated from its surroundings. (a) How longwill it take for the potential of the sphere to increase by 1000 V? (b)How long will it take for the temperature of the sphere to increaseby 5.0 K due to the energy deposited by the electrons? The heatcapacity of the sphere is 14 J/K.
An alpha particle (Z = 2, mass 6.64 x 10-27 kg) approaches to within 1.60 × 10-14 m of a carbon nucleus (Z = 6). (a) What is the maximum Coulomb force on the alpha particle? 10.8 (b) What is the acceleration of the alpha particle at this time? 1.627e27 m/s? (c) What is the potential energy of the alpha particle at the same time? 1.6 Apply the expression for the electrostatic potential energy of two point charges. MeV
Alpha particles are projected toward a gold foil from a distance that is sufficiently large to consider the Coulomb force negligible. The gold nuclei have 118 neutrons and 79 protons. If a 3.60 MeV alpha particle has a scattering angle of 180° and the gold nucleus does not recoil, determine the distance of closest approach of the alpha particle.
Consider an object of mass 56.6 kg. Assume that it s made up of equal numbers of protons, neutrons, and electrons. How many protons does this object contain? Question 1 options: 8.45E+27 1.69E+28 3.38E+28 6.76E+28
A beam of alpha particles is incident on a target of lead. A particular alpha particle comes in “head-on” to a particular lead nu- cleus and stops 6.50 * 10-14 m away from the center of the nucleus. (This point is well outside the nucleus.) Assume that the lead nucleus, which has 82 protons, remains at rest. The mass of the alpha particle is 6.64 * 10-27 kg. (a) Calculate the electrostatic potential energy at the instant that the alpha particle stops. Express your result in joules and in MeV. (b) What initial kinetic energy (in joules and in MeV) did the alpha particle have? (c) What was the initial speed of the alpha particle?
How much kinetic energy must an alpha particle have before its distance of closest approach to a gold nucleus is equal to the nuclear radius (7.0 × 10-¹5 m)?