7. A person is pulling a block at a 20 degree angle . If the force applied to the string is 12N, how much energy is needed to pull the block 10 meters?

Here's how to solve this problem:<br /><br />1. **Determine the horizontal component of the force:** Since the block is moving horizontally, we only care about the horizontal component of the applied force. We can find this using trigonometry:<br /><br /> Horizontal Force = Applied Force * cos(angle)<br /> Horizontal Force = 12 N * cos(20°)<br /> Horizontal Force ≈ 11.28 N<br /><br />2. **Calculate the work done:** Work is defined as force applied over a distance. Since the force and displacement are in the same direction (horizontal), we can calculate the work as follows:<br /><br /> Work = Force * Distance<br /> Work = 11.28 N * 10 m<br /> Work = 112.8 Joules<br /><br />Therefore, approximately 112.8 Joules of energy is needed to pull the block 10 meters.<br />