It depends whereabouts in Cornwall you mean. As an example - Google Earth calculates the driving time from Bournemouth to Penzance as 3 hours 49 minutes for a journey of 195 miles.
Manchester to Newquay, Cornwall is 324.5 miles and should take approx 5 hours 54 minutes according to AA route planner.
The driving distance is 57 miles. The time needed to drive is 1 hour and 8 minutes.
A lot.
36 days!!
Bournemouth is 107 miles SouthWest of London, approximately 2 hours drive.
Depends on which part of Cornwall but about 8 hours.
about 2 hours!
If you are asking about the Cornwall in England, then you can't drive from there to Los Angeles, because of the ocean.
It takes about 5 hours and 35 minutes to drive to Yateley Hampshire to Cornwall.
According the AA Route Planner (GB Edition) the distance is 362.8 miles, this will take about 6 hours and 24 minutes to drive, assuming you take the direct route and there are no stops, accidents, breakdowns or other hold ups en route.
About 2 hours - but it depends on traffic.