Answer:
Ew an sao fan. anyway, it's 0.24m/s^2
Explanation:
Use this equation for 1 dimensional motion with constant acceleration:
Xf = Xi + Vi*T + 0.5A*T^2
Xf is 50 m when Xi is 0m
Vi is 5m/s
A is (7m/s-5m/s)/T = 2m/s/T
So,
50m = 0m + 5m/s *T + 0.5*2m/s/T * T^2
50m = 5m/s * T + 1m/s * T
50m = 6m/s * T
T = 8.33s
A is 2m/s/T
A is 2m/s/8.33s
A is 0.24m/s^2