Chapter 9, Problem 1Q

Describe several situations in which an object is not in equilibrium even though the net force on it is zero

To determine

To Describe: Several situations in which an object is not in equilibrium, even though the net force on it is zero.

Answer to Problem 1Q

Solution: Some situations in which an object is not in equilibrium, but the net force on it is zero are,a carousel that at the beginning is at rest and is activated when it acquires a certain angular acceleration. A spinning top is activated by turning it with two threads in opposite directions. In the amusement park, a sky dream that starts to turn and reaches a certain angular acceleration.

Explanation of Solution

Given info:Objects in equilibrium and net force.

Formula used:

An object is in equilibrium when it satisfies the following conditions:

The net force is zero:

  ${\displaystyle \sum {\text{<mover accent="true"><mo>F</mo><mo>→</mo></mover>}}_{\text{net}}}=0\mathrm{...}\left(1\right)$

The net torque is zero:

  ${\displaystyle \sum \overrightarrow{\tau }=0}\mathrm{...}\left(2\right)$

According to equation (1) and (2), an object can have zero net force but if the resulting torque is nonzero, the object is not in equilibrium.

Conclusion:

Some situations in which the condition (1) but not the condition (2) are satisfied are,a carousel that at the beginning is at rest and is activated when it acquires a certain angular acceleration.A spinning top is activated by turning it with two threads in opposite directions. In the amusement park, a sky dream that starts to turn and reaches a certain angular acceleration.