If the distance between London and New York is 3600km, how long would you expect Concorde to take fly the....

If the distance between London and New York is 3600km, how long would you expect Concorde to take fly the distance at a speed of 1200km/h? The actual flight time is longer than this - why?

You would expect it to take three hours: 3600 / 1200 = 3.

However, it takes longer because when the flight takes off and lands it cannot automatically be going 1200 km/h, but instead needs time to build up to this speed.

speed = distance/ time
So time = distance /speed 3600km/1200km/hr = 3hr