Question 1185336
Here's how to calculate Anne's acceleration:

**(a) Acceleration in km/hr/min:**

1. **Calculate the change in velocity:**
   Change in velocity (Δv) = Final speed - Initial speed
   Δv = 90 km/h - 50 km/h = 40 km/h

2. **Calculate the change in time:**
   Change in time (Δt) = 9:30 AM - 9:00 AM = 30 minutes

3. **Calculate the acceleration:**
   Acceleration (a) = Change in velocity / Change in time
   a = Δv / Δt
   a = 40 km/h / 30 min
   a = 4/3 km/hr/min  or approximately 1.33 km/hr/min

**(b) Acceleration in m/s²:**

1. **Convert the change in velocity to m/s:**
   Δv = 40 km/h * (1000 m/km) * (1 h/3600 s) = 100/9 m/s or approximately 11.11 m/s

2. **Convert the change in time to seconds:**
   Δt = 30 min * 60 s/min = 1800 s

3. **Calculate the acceleration:**
   a = Δv / Δt
   a = (100/9 m/s) / 1800 s
   a = 100 / (9 * 1800) m/s²
   a = 1/162 m/s² or approximately 0.00617 m/s²

**Important Note:** The information about the distance traveled (from kilometer 20 to 55) is not needed to calculate the acceleration.  Acceleration is solely determined by the change in velocity and the change in time.