If an alpha particle (two protons and twoneutrons) is given an initial (nonrelativistic) velocityvat a very far distance and is aimed directly at a gold nucleus (z=79), what is the closest distance d the alpha particle will come to the nucleus?
in this problem you can estimate that the mass of the proton m_p is equal to the mass of the neutron and only consider the effects of a single gold nucleus. assume that the alpha particle comes close enough so that the nucleus is not substantially screened by inner-shell electrons. express your answer in terms of m_p, the permittivity of free space epsilon_0, the magnitude of the electron charge e, and v.

it would be kevlar ^^

it's when something is going so fast it makes a loud noise, breaking the sound barrier, for example: a jet makes a loud noise, not only cause of the jet but because they reached a point where they went so fast that you can year the noise from various parts, kinda like a police car, lets say the car was going   so fast that you hear the siren of the cop car right next to you, but the car is probably a mile a way, it's cos the siren was next to you a few seconds if you understand me

it is given that trillions of microbes make up to 1% to 3% of the body mass.

let's take average of this percentage: 2%

consider the average mass of the human body as 70 kg.

then, trillions of microbes would have mass  

therefore, 100 trillion micro-organisms would weigh:

this is an approximate value and could change depending on the mass of the human body and percentage of the microbes present in it.

average mass per microorganism =