Two cars are driving *towards* an intersection from perpendicular directions. The first car's velocity is $10$ meters per second and the second car's velocity is $6$ meters per second. At a certain instant, the first car is $4$ meters from the intersection and the second car is $3$ meters from the intersection. **What is the rate of change of the distance between the cars at that instant (in meters per second)?** [[☃ radio 1]]