An antiproton (same properties as a proton but with a negative charge, q=-e) is moving in the combined electric and magnetic fields shown below, where E =1200 V/m, B =2.8 T, and v =520 m/s. X X X X X B X X X X X X X X X X X X X X X E a. What are the magnitude and direction of the antiproton's acceleration in this instant? (2 ,marks) b. What would be the magnitude and direction of the antiproton's acceleration if the velocity were reversed? (2 marks)