A 2.53*10^(-6) C charged particle with kinetic energy of 0.0929 J is fired into a uniform magnetic field of magnitude 0.147 T. If the particle moves in a circular path of radius 3.38 m, determine its mass in kg. (answer should be within 2*10^-14 kg) The formula r=mv/qb comes to mind where r is radius (in m), m is mass (in kg), v is velocity (in m/s), q is charge in coulombs, and b is the magnetic field in teslas. Another important formula is Kinetic energy is 0.5mv^(2). where m is mass in kg and v is is m/s (I think). I tried to solve this but I run into the problem of not being able to isolate the m to solve for it. I know that 0.0929 J = 0.5mv^(2) but I still have two unknowns and can't solve for the mass. Otherwise I could insert into r=mv/qb, such as 3.38m=mv/(2.53*10^(-6) C)(0.147 T) It seems like I would need to be given the velocity to be able to solve for the mass, can anyone help??