1.Can an object be in mechanical equilibrium when only a single force acts on it

Question

1.Can an object be in mechanical equilibrium
when only a single force acts on it? Explain.
1.None of these
2. Yes; the object will act back with an equal
and opposite force.
3. No; even one force is too much. There
should be no forces acting on an object.
4. Yes; a single force is necessary to keep the
object in mechanical equilibrium.
5. No; at least one other force is needed to cancel the action of the first force.

2.A hockey puck slides across the ice at a con-
stant speed.
Which of the following is true?
1.The puck can be considered neither at
rest nor in equilibrium.
2. The puck is moving and thus not in equi-
librium.
3. The puck is at rest.
4. It is in equilibrium.
5. None of these

Explanation / Answer

1. The definition of mechanical equilibrium is basically, and object with a net force acting on it is 0. A visualization of the example is an object falling from space. There is no external force, I.E. friction or resistance, and gravity is the only force acting on it. Therefore, it is accelerating and has a non-zero net force. the closest answer choice is 6. 2. The puck is moving at a constant speed. therefore, the reference frame you view the puck at is considered an inertial frame, (frame where a body is subject to know external forces and moves in a straight line at constant velocity). Galilean invariance states that if an interaction (the puck moving) is in at least one inertial reference frame, it is also valid to look at the interaction in any reference frame moving at any arbitrary constant velocity. I.E. if you, the observer, were moving parallel to the puck at the same speed of the puck, it would appear that the puck was at rest. In this reference frame, the puck is both at rest and at equilibrium.

Related Questions

Navigate

• Browse (All)
• Browse 1
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.