Can someone please do this for me

Explanation:

v = u + at    basic kinematic equation

1)  a = (v - u)/t = (90 - 80) / 4 = 2.5 km/hr/s

2) a = (v - u)/t = (5 - 20) / 6 = - 2.5 km/hr/s

3) a = (v - u)/t = (4 - 1) / 2 = 1.5 cm/s/s

4) a = (v - u)/t = (20 - 50) / 15 = - 2.0 km/hr/s

5) a = (v - u)/t = (40 - 5) / 6 = - 5.8 m/s/s

6) a = (v - u)/t = (0 - 4) / 0.5 = - 8 m/s/s

7) v = u + at = 0 + 2(16) = 32 m/s

8) t = (v - u)/a = (0 - 80)/-2 = 40 s

positive reinforcement? ?