Question

At any given moment, there are several different forces acting on an object. Which of the following observations indicate that the forces are not in equilibrium? (Choose all that apply)

a. Constant velocity

b. Acceleration

c. Changing direction

d. Stationary

Answer 1

The observations that indicate the forces are not in equilibrium are:

b. Acceleration

If an object is accelerating, it means that the net force acting on it is not zero.

c. Changing direction

Changing direction implies the presence of a net force, as a force is required to alter the direction of motion.

d. Stationary (if by "stationary" you mean not moving)

If an object is not in motion, it could be at rest or moving at a constant velocity. If it's at rest, the forces may be in equilibrium. If it's moving at a constant velocity, the forces may also be in equilibrium. However, if it's stationary and experiencing acceleration or changing direction, the forces are not in equilibrium.

So, the correct options are b, c, and d.

Answer 2

Acceleration, changing direction, and being stationary indicate that the forces are not in equilibrium.

Step-by-step explanation:

In order for forces to be in equilibrium, the net force acting on the object must be zero. Therefore, if any of the following observations occur, it indicates that the forces are not in equilibrium:

1. Acceleration: If the object is accelerating, it means that there is an unbalanced force acting on it.
2. Changing direction: If the object is changing its direction of motion, it means that the forces acting on it are not balanced.
3. Stationary: If the object is not moving at all, it means that the forces acting on it are not balanced.

Observations that indicate the forces acting on an object are not in equilibrium include acceleration (b) and changing direction (c). When forces are in equilibrium, an object will either remain at rest (d) or move with a constant velocity (a), meaning there is no net force acting upon it, and therefore no acceleration. However, if there is a change in velocity or direction, it suggests an unbalanced force is acting on the object, causing it to accelerate.

For example, when a car accelerates (b), it means there is a net force in the direction of acceleration, and the forces are not equal. Also, if a car is turning (c), it is changing direction, which is a form of acceleration known as centripetal acceleration, indicating that the net forces are not balanced.