When I saw the part about "25 seconds to come to rest", I thought
you were going to ask for the acceleration during the roll to a stop.
But you didn't. That fact isn't needed in order to answer the question
that you did ask.
You said that his landing speed is 300 km/hour.
(300 km/hr) x (1,000 m/km) x (1 hr/3,600sec) =
( 300,000 / 3,600 ) (m / sec) = 83-1/3 m/sec
(about 186 mph)
