A beam of α\alphaα-particles is incident on a thin platinum foil. Some α\alphaα-particles pass close to a platinum nucleus (78195Pt^{195}_{78}\text{Pt}78195Pt) and are deflected.
At the position of closest approach, the distance between the α\alphaα-particle (24He^4_2\text{He}24He) and the platinum nucleus is 6.4 × 10-14 m. Calculate the magnitude of the electrostatic force F F\,F between the α\alphaα-particle and the platinum nucleus at this position. (Take ε0=8.85×10−12 F m−1\varepsilon_0 = 8.85 \times 10^{-12}\text{ F m}^{-1}ε0=8.85×10−12 F m−1 and e=1.60×10−19 Ce = 1.60 \times 10^{-19}\text{ C}e=1.60×10−19 C)
The initial kinetic energy of each α\alphaα-particle is 6.0 MeV6.0\text{ MeV}6.0 MeV. Calculate the magnitude of the initial momentum p p\,p of each α\alphaα-particle. (Take the mass of the α\alphaα-particle to be 6.6 × 10-27 kg)
