An electron (with charge q and mass m) enters a uniform magnetic field b. this electron shows a helical motion with a radius r, and a pitch h. (a) what is the direction of the magnetic field? use the coordinate system provided. (b) if we double the field strength, how would the helical motion change? radius: increases [ ], stays the same [ ], decreases [ ] pitch: increases [ ], stays the same [ ], decreases [ ] (c) find the symbolic expression for the speed of the electron