Final answer:
To solve a problem with changing acceleration, first find the change in velocity and the change in time, then calculate average acceleration using the formula a = Δv / Δt.
Step-by-step explanation:
To solve for a variable in a multi-stage problem involving an acceleration that undergoes an abrupt change, one typically follows a structured approach. Initially, the change in velocity (Δv) must be ascertained, followed by finding the change in time (Δt). With these two values, average acceleration can be calculated using the formula:
a = Δv / Δt
For instance, if a train accelerates from rest (v₀ = 0) to a final speed (vₓ) of 30.0 km/h in a time interval (Δt) of 20.0 seconds, the average acceleration is found by converting the final speed to a consistent unit (m/s) if necessary, determining the change in velocity, and then dividing by the time interval given.