outfile = "projectile_length_results.txt"

-- read projectile's position at its centerpoint
handle = openfile("tempfile", "r")
position = read(handle, "*n")
closefile(handle)

-- Group 4 is the solenoid coil
-- Obtain force on coil, and we assume the 
-- force on projectile is equal but opposite in sign
groupselectblock(4)
force = blockintegral(12) * (-1)

handle = openfile(outfile,"a")
write(handle, position, "\t", force, "\n")
closefile(handle)

exitpost()