Mod-1-Lesson-1B-Balanced and Unbalanced Force.pptx

types of forces

1. UNBALANCED AND BALANCED FORCE SCIENCE 8 MERLIN M. EVASCO

2. MELC Demonstrate how a body responds to changes in motion

3. Specific Objectives: Describe net or unbalanced force Explain how force affects the motion of an object

4. https://www.youtube.com/watch?v=47Flpr491yg https://www.youtube.com/watch?v=bc5o3Piw3bg&t=488s

5. Examine the pictures below showing the pen and the flower vase.

6. Tension Force - the force which is transmitted through a string, rope, or wire when it is pulled tight by forces acting at each end.

7. Normal Force - the upward push exerted by the table which referred to as normal force. ( Fn ). Acts in the opposite direction of gravity.

8. Both the tension force and normal force counteract the pull of gravity ( Fg ) that acts on the objects, which makes them to stay at rest.

9. In both cases, you can now infer that the objects remained at rest because the forces acting on the pen and on the vase are equal in magnitude and in opposite direction and they lie along the same line of action. The forces are said to be balanced.

10. What are balanced forces?

11. So, there will be no motion in an object.

12. Balanced force

13. What are unbalanced forces? Unbalanced forces are those that are in opposite direction and unequal in magnitude.

14. Combining Forces Net Force – the sum of all the forces that act on an object

15. Combining Forces For you to determine the net force or unbalanced force, you have to recognize those forces that act along the same line of action. The algebraic sign + and – are used to indicate the direction of forces.

16. Combining Forces Unlike sign are used for forces acting in opposite direction, like in the case of the ball lying on top of the table. The force of gravity ( Fg ) and normal force ( Fn ) are assign opposite signs. Fn is given positive sign (+) while Fg is given (-) sign. If both Fn and Fg are given a magnitude values of 5 units , then the net force along the line will be zero.

17. pen and the flower vase.

18. The vase stays at rest because it has a normal force of 5 units and gravitational force of 5 units also. Let’s find out the net force of the vase.

19. Using GRESA Method G iven : Fn (Normal force) = 5 units Fg (Gravitational force) = 5 units R equired: Fnet ? E quation: Fnet = Fn + Fg S olution: Fnet = 5 units + (-5 units) = 0 A nswer: Fnet = 0

20. Net force or Unbalanced Force If the sum of the force equate or equal to zero (0), the forces are considered balanced. If the algebraic sum is not equal to zero, the forces are not balanced. The non-zero sum is the net or unbalanced force. This unbalanced or net force would cause a change in a body’s state of motion.

21. Recitation : Identify the situation if it shows balance or unbalanced force. Write your answer in your notebook.

22. Friction Force Friction is a force that acts between surfaces that are in contact with one another.

23. Activity 4: Examine the pictures below. Tell whether there is balance or unbalanced force in each situation.

24. 5. 6.

25. Sample Problem 1: Try to solve this problem about balance and unbalanced forces using G-R-E- S-A method. Write your answer on your notebook.

26. Activity 5 : Try to solve this problem about balance and unbalanced forces using G-R-E- S-A method. Write your answer on your notebook. 1.

27. 2.

28. Assesment : Choose the letter of the correct answer. Write your answer on a separate sheet of paper.

29. .

30. Thank You for listening!