https://www.khanacademy.org/science/cambridge-o-level-physics-cie/x0e04e0cb682fb793:forces/x0e04e0cb682fb793:introduction-to-force/v/intro_to_forces_1 2024-06-21T18:55:31.273097146Z Intro to forces (part 1) A force is a push or pull. There are several types, including: applied (from person or machine), tension (from string or cable), gravity (between masses), normal (perpendicular to surface), friction (moving across a surface), thrust (from pushing something the other way), drag (resistance from air or other fluid), buoyancy (from displacing a fluid), and lift (on wings moving through air). Mahesh Shenoy video https://cdn.kastatic.org/ka_thumbnails_cache/a746e5dc-cec7-4c2e-aec0-89d387ffc5f3_1280_720_base.png Intro to forces (part 1) A force is a push or pull. There are several types, including: applied (from person or machine), tension (from string or cable), gravity (between masses), normal (perpendicular to surface), friction (moving across a surface), thrust (from pushing something the other way), drag (resistance from air or other fluid), buoyancy (from displacing a fluid), and lift (on wings moving through air). https://cdn.kastatic.org/ka-youtube-converted/92Adbb6geHE.mp4/92Adbb6geHE.mp4 598 Forces https://www.khanacademy.org/science/cambridge-o-level-physics-cie/x0e04e0cb682fb793:forces/x0e04e0cb682fb793:introduction-to-force/v/intro_to_forces_2 2026-03-04T21:50:47.824781811Z Intro to forces (part 2) A free body diagram (FBD) models the forces acting on an object. The object is replaced by a square. The individual force vectors are shown as arrows, and magnitudes usually measured in newtons. To determine the net force in the horizontal (x) or vertical (y) direction, add forces pointing in the same direction, and subtract forces in the opposite direction. Mahesh Shenoy video https://cdn.kastatic.org/ka_thumbnails_cache/ef6c5f82-33aa-4061-a55b-379cbbbf2a9c_1280_720_base.png Intro to forces (part 2) A free body diagram (FBD) models the forces acting on an object. The object is replaced by a square. The individual force vectors are shown as arrows, and magnitudes usually measured in newtons. To determine the net force in the horizontal (x) or vertical (y) direction, add forces pointing in the same direction, and subtract forces in the opposite direction. https://cdn.kastatic.org/ka-youtube-converted/P48_vJcY9qw.mp4/P48_vJcY9qw.mp4 587 Forces https://www.khanacademy.org/science/cambridge-o-level-physics-cie/x0e04e0cb682fb793:forces/x0e04e0cb682fb793:action-and-reaction-force/v/newtons-third-law 2025-07-01T10:10:08.145512912Z Newton's third law Forces result from interactions between objects. Newton's third law states that two interacting objects exert equal and opposite forces on each other. Each object in the pair experiences one of the forces in the pair. The forces in the pair have equal strengths even if the two interacting objects have different masses or speeds. The forces in the pair don't balance each other because they act on two different objects. Mahesh Shenoy video https://cdn.kastatic.org/ka_thumbnails_cache/ed233176-22c8-47e9-a20e-3216d02adf0d_1280_720_base.png Newton's third law Forces result from interactions between objects. Newton's third law states that two interacting objects exert equal and opposite forces on each other. Each object in the pair experiences one of the forces in the pair. The forces in the pair have equal strengths even if the two interacting objects have different masses or speeds. The forces in the pair don't balance each other because they act on two different objects. https://cdn.kastatic.org/ka-youtube-converted/9ViLDdSTrMU.mp4/9ViLDdSTrMU.mp4 398 Forces https://www.khanacademy.org/science/cambridge-o-level-physics-cie/x0e04e0cb682fb793:forces/x0e04e0cb682fb793:action-and-reaction-force/a/forces-and-newtons-third-law 2026-05-22T02:40:52.34993014Z Learn and try: Forces and Newton's third law Forces always exist in pairs. Explore how the forces in these pairs compare to each other, and why they don't balance each other. article https://www.khanacademy.org/science/cambridge-o-level-physics-cie/x0e04e0cb682fb793:forces/x0e04e0cb682fb793:introduction-to-force/e/understand-forces 2026-05-17T17:10:34.504190576Z Understand: Forces Check your understanding of forces in this set of free practice questions. Emily Cizmas exercise https://www.khanacademy.org/science/highschool-physics/x6679aa2c65c01e53:motion-and-forces/x6679aa2c65c01e53:forces/e/apply-free-body-diagrams 2026-05-22T02:50:56.444203687Z Apply: Free body diagrams Apply your knowledge of forces and free body diagrams in this set of free practice questions. Emily Cizmas exercise https://www.khanacademy.org/science/highschool-physics/x6679aa2c65c01e53:motion-and-forces/x6679aa2c65c01e53:forces/e/apply-net-force 2026-05-17T17:10:34.504190576Z Apply: Net force Apply your knowledge of net force in this set of free practice questions. Emily Cizmas exercise