Chapter 2, Problem 34A

Justin sets a hockey puck sliding across the ice at a constant speed. Is the puck in equilibrium? Why or why not?

To determine

To identify: Whether the hockey puck is in equilibrium if it is sliding across the ice at a constant speed.

Answer to Problem 34A

Yes, the hockey puck is in equilibrium for the given changes.

Explanation of Solution

Introduction:

Whenever the state of motion or rest of an object is to be changed, force is needed andthe combination of these forces provides the net force on the object.

Now, it is given that the hockey puck is moving at a constant speed, thus it means no net force is exerting on it since its state of motion is not changing. Hence, for the hockey puck it can be written as,

  ${\displaystyle \sum F}=0$

And, it is known that whenever the net force on object is zero, then that object is in equilibrium. Hence, the hockey puck moving at a constant speed is in equilibrium. Such type of equilibrium is called dynamic equilibrium.

Conclusion:

Therefore, the hockey puck is in equilibrium if it is sliding across the ice at a constant speed.