It depends on which part of London and which part of Somerset but around 3 hours.
By car it takes 4 hours
Somerset is a rural county in southwest England and therefore some parts of it will only be accessible by car. The city of bath in Somerset has a very good train service to and from London. Other transport available is the coach from Victoria, London.
About 3 hours in the unlikely event of no hold-ups. I'd leave at least 4 hours (you can use the services if you're early).
About 4 hours and 20 minutes depending on what route you take.
The approximate travel time is one hour and thirty minutes. This depends on traffic and which part of London, since London is huge.
Unless you have a car that can travel on water, you can't do this journey.
About 3 hours by car.
a long time
The distance between London, England and Paris, France is 285 miles. It may take up to $200.00 round trip to travel by car, depending on the price of gas.
It usually takes about 5 hours to travel from Blackpool to London under good road conditions (i.e no traffic jams on the way or stop-offs).
8 hours by motor way - it is a long journey by car
About 12 hours