It depends on where you're coming from and how you choose to travel.
A direct flight from Heathrow, London to Tel Aviv, Israel would approximately take 5 hours 15 minutes.
A direct flight from Ben Gurion Airport in Tel Aviv to Logan Airport in Boston would theoretically be around 11 hours long. However, there are few non-stop flights that do that route and a connection will probably be necessary.
Jerusalem does not have an airport, so you would have to fly into Ben Gurion Airport in Tel Aviv. From Tel Aviv to Jerusalem is an hour and change depending on traffic. Detroit to Ben Gurion would be 13 hours theoretically if you could get a direct flight. I have never seen such a direct flight, so it would take 13 hours + 1.2 hours + layover time.
The approximate travel time from Fort Lauderdale-Hollywood International Airport to Ben Gurion International Airport in Tel Aviv is 16,5 hours. However, there are no direct flights from FLL to TLV, so you will have to change flights in New York.
4 hours
10 hours
The distance between John F. Kennedy airport in New York City and Tel Aviv International Airport in Tel Aviv, Israel is 5660 miles, 9110 km. Depending on headwinds and many other variables, going from New York to Tel Aviv is about a 10 hour flight, and from Tel Aviv to New York is about 12 hours.
4hr 50min London Heathrow (LHR) to Tel Aviv (TLV) by nonstop flight operated by BMI British Midland Airways.
from Newark to tel aviv is usually 9:30 hours and from tel aviv to Newark is 11:00 + it depends on the wind...
According to the ETN website (commercial; refer to the link, below), the flying distance between London, England and Jerusalem, Israel is 3,608 miles (2,242 km).
6 hours
I think it is about 12 hours