3 Electromagnetic Force and Strong Force An atomic nucleus contains two types of particles: protons and neutrons. Neutrons have no charge, while protons have a positive charge of 1.6 x 10-19 C. All nucleons interact via the attractive strong force. To hold the nucleus together, the strong force must overcome the Coulomb repulsion of the protons in the nucleus. (a) A helium-4 nucleus (a particle) contains two neutrons and two protons. It has a radius of about 2 × 10-¹5 m. Estimate the electrostatic potential energy of the two protons. (b) The nuclear binding energy of the a particle includes contributions from the attractive strong interaction of protons and neutrons as well as the repulsive electrostatic interaction of the protons. To get some idea of the relative importance of the two interactions, calculate the ratio of the energy you found in part (a) to the nuclear binding energy of the He nucleus.

2. The electronic structure of atoms and molecules may be investigated using Photoelectron spectroscopy. An electron in a photo electron spectrometer is accelerated from nest by a uniform electric field to a speed of 420 kmis" in 10μs. Use the magnitude of the acceleration estimated in determine the force acting on the electron? questions. جاج 3.8 × 10-21 6/2021 6/2022 kgm/s² D 2 kg. m/s² 3.8x 10-2²3/gm/5² 3.8x10-17 3.8x10-20 ikgm/s²

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2. Charged particle interactions and energy conservation A stationary charge, Q = + 31.0uC, remains fixed in position. A moving charge, q = + 7.70µC, with mass, m = 1.18 x 10 kg, heads toward this stationary charge along the x axis. The moving charge starts at position A with an initial speed of 892 m/s. Point A is 1.64 m from the fixed charge. Point B is 0.550 m from the fixed charge. a. Use energy conservation principles to set up an energy conservation equation for this system. b. Solve the energy conservation equation for the speed of the moving charge, vx, when it reaches point B. q. m >+ x axis Fixed stationary charge

The distance, r, between the proton and electron in the hydrogen atom is about 10^-10m. i) Calculate the electrostatic force between the electron and proton. ii) Determine the value of the potential energy U of the electron in the hydrogen atom. Express your result in electron-volts (eV). Recall 1 eV = 1.6 × 10^−19 J. iii) Determine the value of the kinetic energy of the electron. Express your result in eV. Please answer all parts.

3 Charge Deflector E beam An experiment to look for a charge imbalance between the proton and electron is constructed as shown. A beam of particles moving at speed vo = 1.0 x 106 m/s is prepared in an accelerator. Before striking the detector, the beam passes through a region of length L = 10 m that contains a uniform electric field of strength & = 100 N/C perpendicular to the beam. (a) Where would a proton from the beam be expected to strike the detector? (L.e., how many meters above or below the beam line would it strike?) (b) Where would an electron from the beam be expected to strike the detector? (L.e., how many meters above or below the beam line would it strike?) (c) We do not believe a hydrogen atom has any charge, but an experiment can only put an upper limit on the net charge - not prove that it is zero. Suppose the detector in this experiment is unable to detect a deflection less than 1 nm. I.c., if the deflection is 1 nm or less, the detector will register "0" deflection.…

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