Question

the image shows a pendulum in simple harmonic motion. the pendulum starts at a and swings to e. which labels are correct? check all that apply.
e: net force is zero.
d: velocity is decreasing. acceleration is increasing.
a: velocity is zero.
c: acceleration is maximum.
b: velocity is decreasing. net force is decreasing.
e: velocity is maximum.

Explanation:

• A: Velocity is zero

At the extreme position (A, E), the pendulum momentarily stops before reversing direction, so velocity is zero.

• D: Velocity is decreasing. Acceleration is increasing

As the pendulum moves from C (lowest point, maximum velocity) toward E (extreme position), velocity decreases (kinetic energy converts to potential energy). The restoring force (and thus acceleration, \(a = \frac{F_{\text{net}}}{m}\)) increases as the displacement from the equilibrium (C) grows.

• Incorrect Options:
• E: Net force is not zero (restoring force exists at extreme positions).
• C: Acceleration is minimum (zero) at equilibrium (C), as net force is zero.
• B: From A to C, velocity increases (net force is in the direction of motion, decreasing as it approaches C).
• E: Velocity is zero at E (extreme position), not maximum.

Answer:

A. Velocity is zero.
D. Velocity is decreasing. Acceleration is increasing.