10. Net Force Calculation (Multiple Forces): An object experiences three forces: 10 N to the right, 5 N to the left and 8 N upward.Calculate the net force in both the horizontal and vertical directions 11. Force and Friction A person applies a force of 100 N to push a box across a floor. If the frictional force is 70 N what is the net force acting on the box? 12. Free-Body Diagram Interpretation: A free-body diagram shows an object with a 50 N force upward, a 50 N force downward, and a 20 N force to the right. What can you conclude about the motion of the object? 13. Acceleration of a Falling Object: A 5 kg object is falling freely under gravity. Assuming no air resistance, what is the net force acting on the object? (Use a=9.8m/s^2 14. Newton's First Law Application: A hockey puck slides on ice at a constant speed until it hits a rough patch and slows down. Explain this situation using Newton's First Law. 15. Force Required to Lift an Object: What force is required to lift a 10 kg object at a constant speed? Explain your reasoning. (Hint, Look at question 3 for a)

10. **Net Force Calculation:**<br /><br />* **Horizontal:** 10 N (right) - 5 N (left) = 5 N to the right<br />* **Vertical:** 8 N upward<br /><br />11. **Net Force with Friction:**<br /><br />100 N (applied force) - 70 N (friction) = 30 N in the direction of the applied force.<br /><br />12. **Free-Body Diagram Interpretation:**<br /><br />The vertical forces are balanced (50 N up - 50 N down = 0 N). The only unbalanced force is the 20 N force to the right. Therefore, the object will accelerate to the right. It will not move vertically.<br /><br />13. **Acceleration of a Falling Object:**<br /><br />Weight (force due to gravity) = mass * acceleration due to gravity<br />Weight = 5 kg * 9.8 m/s² = 49 N downward. Since there is no air resistance, this is also the net force.<br /><br />14. **Newton's First Law Application:**<br /><br />Newton's First Law states that an object in motion will stay in motion at a constant velocity unless acted upon by a net force. The hockey puck initially slides at a constant speed because the net force on it is zero (forces like friction are negligible). When it hits the rough patch, the increased friction provides a net force opposing the puck's motion, causing it to slow down.<br /><br />15. **Force Required to Lift an Object:**<br /><br />To lift a 10 kg object at a constant speed, you need to apply a force equal to its weight. This is because a constant speed implies zero acceleration, and therefore zero net force.<br /><br />Weight = mass * acceleration due to gravity<br />Weight = 10 kg * 9.8 m/s² = 98 N<br /><br />Therefore, a force of 98 N upward is required to lift the object at a constant speed.<br />