Answer:
4.44 rpm
Explanation:
= Angular speed
G = Gravitational constant = 6.67 × 10⁻¹¹ m³/kgs²
r = Radius of Europa = 
R = Radius of arm = 6 m
The acceleration due to gravity is given by

Here the centripetal acceleration of the arm and acceleration due to gravity are equal


Converting to rpm


The angular speed of the arm is 4.44 rpm
Answer:
Explanation:
Given


same charge on both masses
potential Energy due to Magnetic Field =Kinetic Energy of Particle


and we know
Force due to magnetic field will Provide centripetal Force


and B is equal for both particles
thus 



I'll just give you the link for it but count it as my answer. http://www.differencebetween.com/difference-between-leptons-and-vs-hadrons/