Sandra is riding a bicycle at 10.0 meters/second. she slows down to 2.0 meters/second in 10 seconds. her acceleration is __
meters/second2.

 Her acceleration is -0.8 m/s²

Explanation:

The initial velocity of Sandra ( u) = 10 m/s

The final velocity of Sandra ( v) = 2 m/s

Time taken by Sandra (t) = 10 s

Let the acceleration of Sandra be 'a'

Using the equation of kinematics, we have

                                                        v = u + at  

                                                   ⇒  2 = 10 + 10a

                                                   ⇒  -8 = 10a

                                                   ⇒

                                                   ⇒ a = -0.8 m/s²

Hence, her acceleration is -0.8 m/s².