Step-by-step explanation:
Given that,
Distance, d = 10.5 km = 10500 m
Time, t = 8 minutes = 480 s
We need to find the unit rate of a train motion. The distance divided by time is equal to the speed of the object.
[tex]\text{Rate}=\dfrac{\text{Distance}}{\text{time}}\\\\=\dfrac{10500\ m}{480\ s}\\\\=21.87\ m/s[/tex]
So, the unit rate is 21.87 m/s.
