1. The problem statement, all variables and given/known data Hello, The question of the problem is: Solenoid, calculate laps of a proton? Someone could help me solve this exercise, but I try not to do this achievement . Would appreciate your help . This is the information that I provided to do the exercise: Picture of the year : http://prntscr.com/3eiwy0 A proton with velocity v inside a solenoid of 10,000 laps , Long L and 1 A current (see figure) is triggered. The proton velocity vector has an angle of 40 ° with respect to the magnetic field direction . Calculate the turns while supplementing the proton travels a distance L , the time to complete each lap and total time T to travel L. The values of the magnitude of the velocity ( in m / s ) and the length of the coil ( L in m) chosen according to the first letter of your name using the following code : A- 10 B- 20 C- 30 D -40 E -50 F- 60 G -70 H-80 ... N -140 O- 150 P -160 Q -170 R -180 S -190 U - 200 U -210 V -220 W -230 ... If your name is Domingo Pérez then v = 40 m / s and L = 160 m . If your name will begin with the same letter then use the number of the next letter to the family name. So if your name is Candido Colón use v = 30 m / s and L = 40 m . 2. Relevant equations 3. The attempt at a solution I try so many times to solve the problems, but for me is impossible to solve, i really appreciate all the help.