Net Forces

1. Please watch the following videos for some info about forces. 2. When two or more forces are acting on the same object, in the SAME direction, you ADD the forces. Net force is a vector, so you must include the direction. The unit of force is a Newton (N).25 N + 20 N = 5 N 45 N 10 N 3. When two forces are acting on the same object in OPPOSITE directions, you subtract the forces. Net force is a vector, so you must include the direction.12 N - 10 N = 22 N 12 N 2 N 4. When forces are BALANCED, the net force is zero (0) To the right To the left 5. A big tractor pulls a box with a force of 400N to the left. A small tractor pulls that same box with a force of 200N to the right. What is the net force on the box and what direction will it move? net force is 600 Nthe box will not move net force is 200 Nthe box will move to the right net force is 200 Nthe box will move to the left. net force is 600 Nthe box will move to the left 6. In the diagram 2 people are pushing books. What is the net force being applied to the books? 25 N 5 N to the right 5 N to the left zero, the forces are balanced 7. In the diagram two people are pushing books. What is the net force being applied to the books? 21 N 19 N to the right 19 N to the left zero, the forces are balanced 9. The boy in the picture is trying to pull a dog on its leash, but the boy and the dog are moving in the same direction. Which of the following best describes this situation? The forces are balanced, and the net force is zero. The forces are unbalanced, and the boys force is greater. The forces are unbalanced, and the dog's force is greater. The forces are balanced, and the dog is stronger than the boy. 10. What is the net force? 15 N 5 N to the left 5 N to the right 15 N left 11. What is the net force? 19 N to the right 4 N to the left 7 N to the right 3 N to the right 12. What is the net force? 25 N 10 N down 5 N up 10 N up 13. These boys are both pulling with 10 N of force. What will happen? The boy in blue will win. They will not move at all. The boy in red will win. Both will fall down.