# Related Rates (2)

- Author:
- Tim Brzezinski

- Topic:
- Calculus, Derivative

**Particle A**starts at the point (50, 0) and

**heads west as a speed of 10 m/s**.

**Particle B**starts at the point (0, 40) and

**heads south at a speed of 5 m/s**. Play to animate, then answer the questions that follow.

## 1.

Determine the rate at which *p, *the distance between *A* and *B*, is changing with respect to time at *t* = 2 sec.

## 2.

Explain why, with respect to the physical context here, at *t* = 2 sec.

## 3.

At what time is ? (You can informally verify by interacting with the applet, but be sure to formally show this using calculus!)