Question

1. in which position is there all kinetic energy (ke) and no potential energy (pe)?

1 point
1
2
3
4
5

1. in which position is ke increasing and pe decreasing?

1 point
1
2
3
4
5
pendulum

Explanation:

Step1: Recall energy concepts

For a pendulum, potential energy is related to height and kinetic energy to speed. At the lowest - point, height is minimum and speed is maximum.

Step2: Analyze pendulum positions

Position 3 is the lowest point of the pendulum's swing. At this position, the height of the pendulum bob above the lowest - point is zero (minimum), so potential energy $PE = mgh$ (where $h = 0$) is zero, and speed is maximum, so kinetic energy $KE=\frac{1}{2}mv^{2}$ is maximum.

Step3: Analyze energy change

When the pendulum moves from a higher position to a lower position, it is losing height and gaining speed. So, when moving from positions 1 or 5 towards position 3, kinetic energy is increasing and potential energy is decreasing. Position 2 is on the way down from a higher position (like 1) to the lowest position 3, so $KE$ is increasing and $PE$ is decreasing.

Answer:

1. 3
2. 2