Final answer:
The magnitude of the laundry cart's acceleration is approximately 13.3 m/s².
Step-by-step explanation:
To calculate the magnitude of acceleration, we can use Newton's second law of motion, which states that force equals mass times acceleration (F = ma).
In this case, the net external force acting on the laundry cart is 60.0 N and its mass is 4.50 kg.
Therefore, we can rearrange the formula to solve for acceleration: a = F / m. Plugging in the values, we get:
a = 60.0 N / 4.50 kg = 13.3 m/s²
Therefore, the magnitude of the laundry cart's acceleration is approximately 13.3 m/s².