1. | \(\dfrac{\pi}{6}\) | 2. | \(\dfrac{\pi}{3}\) |
3. | \(\dfrac{\pi}{2}\) | 4. | \(\dfrac{2\pi}{3}\) |
1. | zero | 2. | \(-\frac12mu^2cos^2\theta\) |
3. | \(-\frac12mu^2sin^2\theta\) | 4. | \(-\frac12mu^2\) |
1. | \(W_1=W_2=W_3\) | 2. | \(W_1>W_2>W_3\) |
3. | \(W_1>W_3>W_2\) | 4. | \(W_1<W_2<W_3\) |