1- Some passengers sit in an airplance which is making a level turn of radius 1km. The airplane moves with uniform circular motion. The speed is 400...

Can I get the answer please..

1- Some passengers sit in an airplance which is making a level turn of radius 1km. The airplane moves with uniform circular motion. The speed is 400 km/h. What is this speed in m/sec?

2.Which of the following are true for an object traveling with uniform circular motion? (there may be more than one correct answers for this question)