The acceleration of a car going at a steady speed of 60 mph is 0 m/s².

Here's why:

* Acceleration is the rate of change of velocity.

* Velocity includes both speed and direction.

* If a car is going at a steady speed in a straight line, its velocity is not changing.

* Since the velocity is not changing, the acceleration is zero.

Let me know if you'd like to explore other scenarios!