Answer:
1 m/s
Step-by-step explanation:
Given that :
Speed of runner A (Va) = 10m/s
Speed of runner B (Vb) = 9m/s
The velocity of runner A relative to runner B;
Vab = Va - Vb
Vab = 10m/s - 9m/s
Vab = 1 m/s
Hence, the velocity of runner A relative to the velocity of runner B is 1 m/s