Question
The diagram shows a simple pendulum. Neglecting friction, what happens to the total mechanical energy as the pendulum swings from position A to position B?
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Responses
It decreases.
It decreases.
It increases.
It increases.
It remains the same.
It remains the same.
It is not conserved.
The correct response is: It remains the same.
The correct answer is: "It remains the same."
To determine the change in total mechanical energy as the pendulum swings from position A to position B, we need to understand the concept of mechanical energy and how it relates to the motion of a pendulum.
Mechanical energy can be divided into two forms: potential energy and kinetic energy. Potential energy is the energy due to an object's position relative to other objects, while kinetic energy is the energy due to an object's motion.
In the case of a simple pendulum, the potential energy is highest when the pendulum is at its highest point (position A). As the pendulum swings down towards position B, some of this potential energy is converted into kinetic energy as the pendulum gains speed. At position B, the pendulum is at its lowest point, so the potential energy is at its minimum, while the kinetic energy is at its maximum.
According to the principle of conservation of mechanical energy, the total mechanical energy (the sum of potential energy and kinetic energy) of a system remains constant if there are no external forces, such as friction, acting on the system. However, in this question, it is mentioned that we can neglect friction. This means that there are no external forces dissipating energy, so we can assume that there is no change in mechanical energy.
Therefore, the answer to the question is: It remains the same.