Simplify the following text for a Grade 6 native English-speaking person.
Original: After passing about 65 km ( 45 mi ) east of Okinawa , it accelerated its forward motion to 75 km\/h ( 46 mph ) .
Simplified: After passing about 65 km ( 45 mi ) east of Okinawa , it sped up and was then moving at 75 km\/h ( 46 mph ) .