In the Rutherford experiment, the knocking $($impact$)$ parameter for alpha

particles sent to the gold plate is $16fm.$

a$)$ Since the scattering angle is $75,$ what is the kinetic energy of the

alpha particles sent?

b$)$ Assuming that the alpha particles are sent with the same energy,

and if the scattering angle is $90,$ what is the kinetic energy of the alpha

particle at the shortest distance between the alpha particles and the

nucleus?