Hi there!
We can use the following kinematic equation to solve:
vf² = vi² + 2ad
vf = Final velocity
vi = Initial velocity
a = acceleration
d = displacement
Plug in the given values:
45² = 30² + 2a(300)
2025 = 900 + 600a
Solve:
1125 = 600a
a = 1.875 m/s²