https://www.khanacademy.org/science/cambridge-o-level-physics-cie/x0e04e0cb682fb793:forces/x0e04e0cb682fb793:introduction-to-force/v/contact-forces-dynamics-ap-physics-1-khan-academy 2022-10-05T03:05:09.337066799Z Contact Forces In order for objects to exert a contact force, the objects must be touching. Common examples of contact forces include tension, the normal force, and friction. Contact forces arise due to a large number of long-range forces acting over very small scales. David SantoPietro video https://cdn.kastatic.org/ka_thumbnails_cache/2cb62389-22ea-459b-9181-495f81e4389b_1280_720_base.png Contact Forces In order for objects to exert a contact force, the objects must be touching. Common examples of contact forces include tension, the normal force, and friction. Contact forces arise due to a large number of long-range forces acting over very small scales. https://cdn.kastatic.org/ka-youtube-converted/BtQnTyGq4sI.mp4/BtQnTyGq4sI.mp4 510 Balanced and unbalanced forces https://www.khanacademy.org/science/cambridge-o-level-physics-cie/x0e04e0cb682fb793:forces/x0e04e0cb682fb793:introduction-to-force/e/force-its-effects-and-types 2026-04-06T02:41:58.374508961Z Force, its effects and types Let's solve some questions on force, its effects and types Vibhor Pandey exercise 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 Balanced and unbalanced 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 Balanced and unbalanced forces 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 https://www.khanacademy.org/science/physics/forces-newtons-laws/newtons-laws-of-motion/v/balanced-and-unbalanced-forces 2024-01-16T04:11:35.384208864Z Balanced and unbalanced forces When forces in a particular dimension cancel each other out, they're balanced and result in zero net force. When forces in a particular dimension do not cancel each other out, they're unbalanced and result a nonzero net force. Explore balanced and unbalanced forces through five different scenarios involving a rock and various forces acting on it. Sal Khan video https://cdn.kastatic.org/googleusercontent/LKDY3C-4WFq-cacjqiG2MkgbIId1gEwcyHvTCgoYWUDPZf7sCOJcm_TQCqRY_5MGQYYZlm3ghv_6hChW92cCYH74 Balanced and unbalanced forces When forces in a particular dimension cancel each other out, they're balanced and result in zero net force. When forces in a particular dimension do not cancel each other out, they're unbalanced and result a nonzero net force. Explore balanced and unbalanced forces through five different scenarios involving a rock and various forces acting on it. https://cdn.kastatic.org/ka-youtube-converted/oNgo9bbDi7Q.mp4/oNgo9bbDi7Q.mp4 491 Balanced and unbalanced forces https://www.khanacademy.org/science/physics/forces-newtons-laws/newtons-laws-of-motion/v/unbalanced-forces-and-motion 2022-11-16T04:22:43.7414897Z Unbalanced forces and motion Use your knowledge of balanced and unbalanced forces to evaluate four statements related to the behavior of objects when acted on by forces and to determine whether each statement is true or false. Sal Khan video https://cdn.kastatic.org/googleusercontent/GLJ00BQ1bzpb6J8pZ6A6xtW3H6-SYnPYYsoumt8PyiXtHru9Fv_pJQapJmTj0Yyqr0MQIKPdwQOOgie7THbx2dwE Unbalanced forces and motion Use your knowledge of balanced and unbalanced forces to evaluate four statements related to the behavior of objects when acted on by forces and to determine whether each statement is true or false. https://cdn.kastatic.org/ka-youtube-converted/IgYUR7aFY-c.mp4/IgYUR7aFY-c.mp4 397 Balanced and unbalanced forces https://www.khanacademy.org/science/mh-grade-8-science/x0f256b8de9c7cf34:force-and-pressure/x0f256b8de9c7cf34:force/e/balanced-and-unbalanced-forces 2026-04-27T08:40:32.356784737Z Balanced and unbalanced forces Let's solve some questions! vibhor exercise