ds/dt represents the derivative with respect to time. It measures how much one variable changes with respect to another variable (usually time).
Velocity is defined as the derivative of displacement with respect to time, representing how fast an object's position changes over time.
Acceleration is defined as the derivative of velocity with respect to time, indicating how quickly an object's velocity changes over time.
The chain rule allows us to find derivatives when functions are composed together, such as finding ds/dt when s depends on multiple variables.