What are the forces acting on an elevator as it moves from rest upward and stops at its floor.
Discuss the forces including tension force (on cable or string), gravitational force, and net force when an elevator is at rest. Which law does this support? Which force can you attribute to the reading on your spring scale?
When an elevator is moving upward from rest and stops at its floor, there are several forces at play. The main forces are tension force, gravitational force, and the net force.
1. Tension force (on the cable or string): The tension force acts on the cable or string that supports the elevator. This force is responsible for lifting the elevator and keeping it suspended in the air. The tension force is equal to the weight of the elevator plus the weight of its occupants.
2. Gravitational force: The gravitational force acts downward on the elevator. This force is due to the Earth's gravity and is responsible for pulling objects towards the Earth's surface. The gravitational force acts on the elevator and its occupants, causing them to have weight.
3. Net force: When the elevator is at rest, the net force on it is zero. This means that the upward tension force is equal and opposite to the downward gravitational force. The elevator remains stationary because the forces are balanced.
The above discussion is in accordance with Newton's First Law of Motion, also known as the law of inertia. This law states that an object at rest will remain at rest, and an object in motion will continue moving in a straight line at a constant velocity, unless acted upon by an external force. In the case of the elevator at rest, the net force is zero, and therefore, according to Newton's First Law, it will remain at rest.
The reading on the spring scale can be attributed to the tension force acting on it. The spring scale measures the force exerted on it, and in this case, the force exerted on the scale is equal to the tension force in the cable or string. Hence, the reading on the spring scale gives us an indication of the tension force, which is responsible for supporting the elevator and its occupants.