An astronaut has left the international space station to test a new space scooter. her partner measures the following velocity changes, each taking place in a time interval 11.3 s . what are the average acceleration in each interval?

1.) at the beginning of the interval the astronaut is moving toward the right along the x-axis at 15.0 m/s, and at the end of the interval she is moving toward the right at 5.30 m/s.
a =
2.) at the beginning she is moving toward the left at 5.30 m/s. and at the end she is moving toward the left at 15.0 m/s.
a = ? ?
3.) at the beginning she is moving toward the right at 15.0 m/s, and at the end she is moving toward the left at 15.0 m/s.
a =