Oh man its a Sunday evening here, my brain struggles to work at the best of times let alone Sundays

Ok so acceleration = velocity/time
so Vel/Accel = time
Velocity = 500IPM so divide by 60 to get Inch per second = 8.333333333
Accel = 50 inch/s/s
so
8.33333/50 = 0.16 seconds
Hope thats right

Hood