8. (12 points) A long straight wire carries a current I to the right. Ignore gravity when analyzing the forces on electrons. Extra space is given on the next page. a) Sketch a physical representation of the wire's magnetic field both above and below the wire. You can assume your representation is for a cross-sectional slice of the field in the plane of the paper/screen. Your sketch should use dots ( . ) to represent out of the page and an ( x ) to represent into the page. You should rep- resent larger magnetic field by using larger symbols (smaller x vs larger X). There should be at least 8 loca- tions (4 above and 4 below) at which you represent the field. Not all the positions can be the same dis- tance to the wire and one of the positions should be at point P. (b) If electrons are moving through point P, and they experience a force directly away from the wire (upwards in the figure), what direction are the electrons moving? Explain the reasoning behind your an- swer . (c) Assume there is a small metal ball with an Avogadro's number (6.02 x 1023) of excess electrons travel- ing at 25 m/s through point P in the direction you answered in part (b). If the magnetic field strength at point P is 3 T (similar to what can be found in MRI machines), how much force is exerted on the ball? (d) Use Known Values and Order of Magnitude sensemaking techniques to grasp how large the force in part (c) is. How many times larger is the magnetic force on the ball in part (c) than the weight on a 60 kg hu- man? . P