7. What is the magnitude of the resultant force on the key ring?

To determine the magnitude of the resultant force on the key ring, you would need to know the individual forces acting on the key ring and their directions. The resultant force is found by vector addition of all these forces. If you have forces at angles, you can break them down into their components (using sine and cosine) and then sum the x and y components separately. Finally, use the Pythagorean theorem to find the magnitude of the resultant force from these components. It's essential to pay attention to the direction of each force. A common mistake is forgetting to account for negative components when forces act in opposite directions. This can lead to an inaccurate total force. If you're unsure, drawing a diagram can help visualize how forces interact!