To find the angle A between the velocity and the magnetic field at the location of the particle, we can use the formula for the magnetic force on a charged particle moving in a magnetic field:
F = qvBsinθ
Where:
F = Magnetic force on the particle (1.71x10^(-4) N)
q = Charge of the particle (2.5x10^(-6) C)
v = Velocity of the particle (1000 m/s)
B = Magnetic field strength (0.2 T)
θ = Angle between the velocity and the magnetic field
Rearranging the formula to solve for θ:
θ = arcsin(F / (qvB))
Let's substitute the values into the formula and calculate θ:
θ = arcsin((1.71x10^(-4) N) / ((2.5x10^(-6) C) * (1000 m/s) * (0.2 T)))
Using a calculator, the value of θ comes out to be approximately 15.9 degrees.
Therefore, the size of the angle A (in degrees) between the velocity and the magnetic field at the location of the particle is most nearly 15.9 degrees. The closest option is 15.9.