https://www.khanacademy.org/science/ms-physics/x1baed5db7c1bb50b:motion-and-forces/x1baed5db7c1bb50b:forces/v/forces 2025-06-20T17:00:10.254290374Z Forces A force is a push or a pull. Types of contact forces include the normal and friction forces. Types of non-contact forces include the gravitational, electric, and magnetic forces. When two or more forces act on an object in the same direction, their effects add. In opposite directions, their effects subtract. Adding and subtracting all of the individual forces this way gives the net force on the object. If the net force is zero, the forces are balanced. If not zero, the forces are unbalanced. Mahesh Shenoy video https://cdn.kastatic.org/ka_thumbnails_cache/c12eb1bc-2efa-437c-a24e-271bfe5b4c6c_1280_720_base.png Forces A force is a push or a pull. Types of contact forces include the normal and friction forces. Types of non-contact forces include the gravitational, electric, and magnetic forces. When two or more forces act on an object in the same direction, their effects add. In opposite directions, their effects subtract. Adding and subtracting all of the individual forces this way gives the net force on the object. If the net force is zero, the forces are balanced. If not zero, the forces are unbalanced. https://cdn.kastatic.org/ka-youtube-converted/emZftp_UBKs.mp4/emZftp_UBKs.mp4 434 Types of forces https://www.khanacademy.org/science/cosmology-and-astronomy/universe-scale-topic/light-fundamental-forces/v/four-fundamental-forces 2021-04-04T12:52:27Z Four fundamental forces Gravity, Weak, Electromagnetic and Strong Sal Khan video https://cdn.kastatic.org/googleusercontent/QYfPEn_0G-fMlVMynWqJfVzR9Ezim_rOy3LBUEZ0PNh6lFscEU3bCXVzsdfs8v5DFBPG_rfdUI-PaDOU-1me3D4s Four fundamental forces Gravity, Weak, Electromagnetic and Strong https://cdn.kastatic.org/ka-youtube-converted/FEF6PxWOvsk.mp4/FEF6PxWOvsk.mp4 629 Types of forces https://www.khanacademy.org/science/ms-physics/x1baed5db7c1bb50b:non-contact-interactions/x1baed5db7c1bb50b:gravitational-force/v/gravitational-force 2025-06-20T17:00:10.254290374Z Gravitational force Objects with mass exert gravitational forces on each other. Gravitational forces are always attractive. Gravity is a non-contact force that does not require objects be touching in order to act. Instead, the gravitational force can be modeled as acting through a gravitational field. The strength of the gravitational forces two objects exert on each other depends on the masses of both objects, as well as the distance between their centers of mass. Mahesh Shenoy video https://cdn.kastatic.org/ka_thumbnails_cache/5c4f03d6-491b-4a7a-8df2-d28fd6b0890b_1280_720_base.png Gravitational force Objects with mass exert gravitational forces on each other. Gravitational forces are always attractive. Gravity is a non-contact force that does not require objects be touching in order to act. Instead, the gravitational force can be modeled as acting through a gravitational field. The strength of the gravitational forces two objects exert on each other depends on the masses of both objects, as well as the distance between their centers of mass. https://cdn.kastatic.org/ka-youtube-converted/R0XFqHBZfHc.mp4/R0XFqHBZfHc.mp4 489 Types of forces https://www.khanacademy.org/science/ms-physics/x1baed5db7c1bb50b:non-contact-interactions/x1baed5db7c1bb50b:gravitational-force/a/gravitational-forces 2026-03-19T16:52:50.562478363Z Gravitational force Use a PhET simulation to investigate the gravitational forces two masses exert on each other. Explore how mass and distance affect the strengths of gravitational forces. article https://www.khanacademy.org/science/ms-physics/x1baed5db7c1bb50b:non-contact-interactions/x1baed5db7c1bb50b:gravitational-force/e/understand-gravitational-forces 2025-12-19T15:30:45.999152142Z Understand: gravitational force Check your understanding of gravitational force in this set of free practice questions. Khan Academy exercise https://www.khanacademy.org/science/ms-physics/x1baed5db7c1bb50b:non-contact-interactions/x1baed5db7c1bb50b:gravitational-force/e/apply-gravitational-force 2026-04-08T01:15:04.085520103Z Apply: gravitational force Apply your knowledge of gravitational force in this set of free practice questions. Emily Cizmas exercise https://www.khanacademy.org/science/ms-physics/x1baed5db7c1bb50b:non-contact-interactions/x1baed5db7c1bb50b:electric-and-magnetic-forces/v/electric-force 2025-06-20T17:00:10.254290374Z Electric force Objects with charge exert electric forces on each other. Like charges repel each other, and opposite charges attract each other. The electric force is a non-contact force that does not require objects be touching in order to act. Instead, the electric force acts through an electric field. The strength of the electric forces two objects exert on each other depends on the charges of both objects, as well as the distance between them. Mahesh Shenoy video https://cdn.kastatic.org/ka_thumbnails_cache/4010b695-0a3a-45eb-b440-322b134d7693_1280_720_base.png Electric force Objects with charge exert electric forces on each other. Like charges repel each other, and opposite charges attract each other. The electric force is a non-contact force that does not require objects be touching in order to act. Instead, the electric force acts through an electric field. The strength of the electric forces two objects exert on each other depends on the charges of both objects, as well as the distance between them. https://cdn.kastatic.org/ka-youtube-converted/nIGEp5x0Ab4.mp4/nIGEp5x0Ab4.mp4 452 Types of forces https://www.khanacademy.org/science/telangana-class-8-science/x17f7017799a605d2:force/x17f7017799a605d2:contact-forces/v/contact-forces-in 2025-07-09T07:59:38.556597776Z Contact forces Let's learn about contact forces Skyloom (Dubbing) video https://cdn.kastatic.org/googleusercontent/ZCdwTudJg6e6n-P2gsaUborP4izvMsGo71pvEVlX9dNYWcLXcP7VHkWpn2grt4TUP1KoJLQP9NswyHBuBLSFTBw Contact forces Let's learn about contact forces https://cdn.kastatic.org/ka-youtube-converted/U3zZS806H4s.mp4/U3zZS806H4s.mp4 550 Types of forces https://www.khanacademy.org/science/physics/forces-newtons-laws/normal-contact-force/v/normal-force-and-contact-force 2023-09-10T17:11:17.624018169Z Normal force and contact force Explore Newton's First Law of Motion with two blocks of ice, one stationary and one moving. Understand how the force of gravity and the normal force from the ice keep the blocks from accelerating downwards. Dive into the atomic level to see how electromagnetic repulsion between molecules creates the normal force. Sal Khan video https://cdn.kastatic.org/googleusercontent/2s5Eqf0r-mKPq87-_d914hXtck2x17ucaB3Ds9g2JEVmGtaibNNFNqUgxSu5qZj-XfCH9JlCWtSNRnS22CFXB_mH Normal force and contact force Explore Newton's First Law of Motion with two blocks of ice, one stationary and one moving. Understand how the force of gravity and the normal force from the ice keep the blocks from accelerating downwards. Dive into the atomic level to see how electromagnetic repulsion between molecules creates the normal force. https://cdn.kastatic.org/ka-youtube-converted/1WOrgrIcQZU.mp4/1WOrgrIcQZU.mp4 438 Types of forces https://www.khanacademy.org/science/physics/forces-newtons-laws/normal-contact-force/v/normal-force-in-an-elevator 2023-09-10T17:11:17.624018169Z Normal force in an elevator Explore the concept of normal force in different scenarios, particularly in elevators. Understand how acceleration and velocity impact the normal force, and how our bodies perceive these changes. This knowledge is crucial for understanding physical processes, making it a key topic for premed studies. Sal Khan video https://cdn.kastatic.org/googleusercontent/UAetbGNAavVkxHfqOmHAF9spCoclHY4PpdeuP6UaWNdKl2PjZeL0QOqDEUoeg7o_fRQk-3dyHOSQRn7G7kWnfM-5 Normal force in an elevator Explore the concept of normal force in different scenarios, particularly in elevators. Understand how acceleration and velocity impact the normal force, and how our bodies perceive these changes. This knowledge is crucial for understanding physical processes, making it a key topic for premed studies. https://cdn.kastatic.org/ka-youtube-converted/hoRsHNSrMpc.mp4/hoRsHNSrMpc.mp4 709 Types of forces https://www.khanacademy.org/science/physics/forces-newtons-laws/normal-contact-force/v/more-on-normal-force-shoe-on-floor 2024-11-06T15:51:57.252510189Z Normal force examples Normal force is the perpendicular component of the force that a surface exerts on an object in contact with it. Normal force is always directed away from the surface. Learn how to determine the normal force acting on an object in a variety of scenarios. David SantoPietro video https://cdn.kastatic.org/googleusercontent/xq4CfBxFyMJ-bI5Ajd3YXpHZ8KrYqzAQSZx-anUCiPBIZalLIBf9dAEnIWrEjgO4QyX4xko_8q-hEVL8vT2uvyM Normal force examples Normal force is the perpendicular component of the force that a surface exerts on an object in contact with it. Normal force is always directed away from the surface. Learn how to determine the normal force acting on an object in a variety of scenarios. https://cdn.kastatic.org/ka-youtube-converted/1CTdrWFNkGo.mp4/1CTdrWFNkGo.mp4 645 Types of forces https://www.khanacademy.org/science/physics/forces-newtons-laws/normal-contact-force/v/more-on-normal-force-shoe-on-wall 2021-02-07T17:14:01Z More on Normal force (shoe on wall) David shows how to determine the normal force for a shoe shoved against a wall with a diagonal force. David SantoPietro video https://cdn.kastatic.org/googleusercontent/4BHah8nJ03WHWAKhVE-yokoPkfRTnf56MZ9U3iRT93bcHhSHRfsrnA-Nm314xgOKOonzem1yuJYrmdiNoH2uw9xU More on Normal force (shoe on wall) David shows how to determine the normal force for a shoe shoved against a wall with a diagonal force. https://cdn.kastatic.org/ka-youtube-converted/N_J5SeI_62U.mp4/N_J5SeI_62U.mp4 406 Types of forces https://www.khanacademy.org/science/highschool-physics/x6679aa2c65c01e53:motion-and-forces/x6679aa2c65c01e53:forces/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 Types of forces https://www.khanacademy.org/science/highschool-physics/x6679aa2c65c01e53:motion-and-forces/x6679aa2c65c01e53:forces/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 Types of forces https://www.khanacademy.org/science/physics/forces-newtons-laws/tension-tutorial/v/tension-part-2 2023-09-10T17:11:17.624018169Z Introduction to tension (part 2) Expand your understanding of the concept of tension in physics with a slightly more difficult tension problem that focuses on stationary points and net forces. Learn how to calculate tension in wires using trigonometry, vector components, and algebra. Understand how tension varies in different wires based on their angle and force of gravity. Sal Khan video https://cdn.kastatic.org/googleusercontent/zat02SbAcQbogQC2RyvqRCg3EF2_FltR-kf_tdnt8QcEMQ3VQFcOhM7HYimIKgi8gFbIXbpGE91AtCuPM8trxPf7 Introduction to tension (part 2) Expand your understanding of the concept of tension in physics with a slightly more difficult tension problem that focuses on stationary points and net forces. Learn how to calculate tension in wires using trigonometry, vector components, and algebra. Understand how tension varies in different wires based on their angle and force of gravity. https://cdn.kastatic.org/ka-youtube-converted/zwDJ1wVr7Is.mp4/zwDJ1wVr7Is.mp4 619 Types of forces https://www.khanacademy.org/science/class-7-science/x0c8b40bd4b242f0b:forces-and-machine/x0c8b40bd4b242f0b:forces-its-effects-and-types/v/types-of-forces 2023-06-26T04:10:39.513125705Z Types of forces What are the different types of forces? Let's find out! Vibhor Pandey video https://cdn.kastatic.org/googleusercontent/ZCdwTudJg6e6n-P2gsaUborP4izvMsGo71pvEVlX9dNYWcLXcP7VHkWpn2grt4TUP1KoJLQP9NswyHBuBLSFTBw Types of forces What are the different types of forces? Let's find out! https://cdn.kastatic.org/ka-youtube-converted/321RIc7Pkb4.mp4/321RIc7Pkb4.mp4 543 Types of forces https://www.khanacademy.org/science/in-in-class11th-physics/in-in-class11th-physics-laws-of-motion/in-in-class11-introduction-to-forces-and-free-body-diagrams-ap/v/types-of-forces-and-free-body-diagrams 2020-08-28T01:50:20Z Types of forces and free body diagrams Sal defines and compares tension, weight, friction and normal forces using free body diagrams. video https://cdn.kastatic.org/googleusercontent/-uujch5SZl_27TTMB_N2W2RYSXzWbIjeHDWEQx45jyaN7UHGQk5Nqs6i2CW6nQVFRpTJeWed0AhaEQoSjhZVclSt Types of forces and free body diagrams Sal defines and compares tension, weight, friction and normal forces using free body diagrams. https://cdn.kastatic.org/ka-youtube-converted/MaabUHLIIXA.mp4/MaabUHLIIXA.mp4 483 Types of forces https://www.khanacademy.org/science/ap-college-physics-1/xf557a762645cccc5:force-and-translational-dynamics/xf557a762645cccc5:forces-and-systems/v/forces-and-free-body-diagrams 2025-10-06T13:00:43.565068281Z Forces and free-body diagrams A force is a vector quantity that describes a push or pull. A variety of contact forces (e.g., normal force, friction) and non-contact forces (e.g., gravity) may act on an object simultaneously. A free-body diagram is a model that shows each of the external forces exerted on an object. Forces are represented as vector arrows originating from the representation of the center of mass, such as a dot. A free-body diagram is useful for determining the net force on an object, which is the vector sum of all the individual forces acting on the object. Mahesh Shenoy video https://cdn.kastatic.org/ka_thumbnails_cache/42a78503-f228-4155-b96d-e36bfb3cce31_1280_720_base.png Forces and free-body diagrams A force is a vector quantity that describes a push or pull. A variety of contact forces (e.g., normal force, friction) and non-contact forces (e.g., gravity) may act on an object simultaneously. A free-body diagram is a model that shows each of the external forces exerted on an object. Forces are represented as vector arrows originating from the representation of the center of mass, such as a dot. A free-body diagram is useful for determining the net force on an object, which is the vector sum of all the individual forces acting on the object. https://cdn.kastatic.org/ka-youtube-converted/i447NWNpScM.mp4/i447NWNpScM.mp4 734 Types of forces https://www.khanacademy.org/science/mh-grade-8-science/x0f256b8de9c7cf34:force-and-pressure/x0f256b8de9c7cf34:force/v/force-has-direction-and-magnitude 2023-07-03T13:44:16.33096147Z Force has direction and magnitude A force is made up of two things - direction and magnitude. Let's see how! Vibhor Pandey video https://cdn.kastatic.org/googleusercontent/ZCdwTudJg6e6n-P2gsaUborP4izvMsGo71pvEVlX9dNYWcLXcP7VHkWpn2grt4TUP1KoJLQP9NswyHBuBLSFTBw Force has direction and magnitude A force is made up of two things - direction and magnitude. Let's see how! https://cdn.kastatic.org/ka-youtube-converted/_F3WC9g2-x8.mp4/_F3WC9g2-x8.mp4 75 Types of forces https://www.khanacademy.org/science/in-in-class11th-physics/in-in-class11th-physics-laws-of-motion/in-in-class11-introduction-to-forces-and-free-body-diagrams-ap/a/forces-introduction-and-free-body-diagrams-ap1 2021-04-29T07:50:48Z Introduction to forces and free body diagrams review Review the key concepts and skills for forces, including how to draw free body diagrams. article https://www.khanacademy.org/science/highschool-physics/x6679aa2c65c01e53:motion-and-forces/x6679aa2c65c01e53:forces/e/understand-forces 2024-06-28T19:16:58.273985971Z Understand: forces Check your understanding of forces in this set of free practice questions. Emily Cizmas exercise https://www.khanacademy.org/science/in-in-class11th-physics/in-in-class11th-physics-laws-of-motion/in-in-class11-newtons-second-law/e/forces-and-motion 2023-05-02T10:39:57.848656306Z Forces and motion Let's solve some problems to better understand the behavior of forces that act on objects, and their effects on motion. In the process, we will clear some common misconceptions. Aakash Bagga exercise https://www.khanacademy.org/science/ap-college-physics-1/xf557a762645cccc5:force-and-translational-dynamics/xf557a762645cccc5:forces-and-systems/e/free-body-diagrams-ap-physics-1 2025-12-05T19:00:51.330156005Z Forces and free-body diagrams Apply your knowledge of forces and free-body diagrams in this set of free practice questions. Sean exercise https://www.khanacademy.org/science/highschool-physics/x6679aa2c65c01e53:motion-and-forces/x6679aa2c65c01e53:forces/e/apply-free-body-diagrams 2024-06-28T19:16:58.273985971Z 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 2024-06-28T19:16:58.273985971Z Apply: net force Apply your knowledge of net force in this set of free practice questions. Emily Cizmas exercise https://www.khanacademy.org/science/class-7-science/x0c8b40bd4b242f0b:forces-and-machine/x0c8b40bd4b242f0b:uses-and-disadvantages-of-friction/v/friction-and-its-types 2025-06-15T10:36:52.588065596Z Friction and its types In this video, understand the concept of friction, why it occurs, and the difference between static and sliding (kinetic) friction. Perfect for students and curious minds who want simple, clear explanations with visuals! Chandan Ganotra video https://cdn.kastatic.org/googleusercontent/ZCdwTudJg6e6n-P2gsaUborP4izvMsGo71pvEVlX9dNYWcLXcP7VHkWpn2grt4TUP1KoJLQP9NswyHBuBLSFTBw Friction and its types In this video, understand the concept of friction, why it occurs, and the difference between static and sliding (kinetic) friction. Perfect for students and curious minds who want simple, clear explanations with visuals! https://cdn.kastatic.org/ka-youtube-converted/pSV9DdD0jgI.mp4/pSV9DdD0jgI.mp4 325 Types of forces https://www.khanacademy.org/science/physics/forces-newtons-laws/inclined-planes-friction/v/static-and-kinetic-friction-example 2022-11-16T04:22:43.7414897Z Static and kinetic friction example Explore how different kinds of friction impact acceleration with the example of a block of wood on some dirt. Determine the acceleration of the block when pushed with a force of 100 N, taking into account the coefficients of static and kinetic friction. Sal Khan video https://cdn.kastatic.org/googleusercontent/97zdpMaVFtIOTZbqErnGQR7iAIyteba2JEmaQrXjobTBdXngkJEKfvQrHknQ9GIXGXSBhLF-_8InFa2KLLgV4Xg Static and kinetic friction example Explore how different kinds of friction impact acceleration with the example of a block of wood on some dirt. Determine the acceleration of the block when pushed with a force of 100 N, taking into account the coefficients of static and kinetic friction. https://cdn.kastatic.org/ka-youtube-converted/ZA_D4O6l1lo.mp4/ZA_D4O6l1lo.mp4 590 Types of forces https://www.khanacademy.org/science/ap-college-physics-1/xf557a762645cccc5:force-and-translational-dynamics/xf557a762645cccc5:friction-force/a/what-is-friction 2025-08-01T20:15:54.060235323Z Friction Learn how to measure and model the force of friction. Distinguish between kinetic and static friction. article https://www.khanacademy.org/science/in-in-class-11-physics-cbse-hindi/in-in-11-laws-of-motion-hindi/friction-hindi/a/friction-ap-physics-1 2021-04-29T07:52:35Z Friction review Review the key concepts, equations, and skills for friction, including how to find the direction and magnitude of the friction force. article https://www.khanacademy.org/science/class-7-science/x0c8b40bd4b242f0b:forces-and-machine/x0c8b40bd4b242f0b:forces-its-effects-and-types/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/telangana-class-8-science/x17f7017799a605d2:friction/x17f7017799a605d2:friction-and-its-types/e/force-of-friction-and-its-types 2025-06-15T10:36:52.588065596Z Force of friction and its types Force of friction and its types Chandan Ganotra exercise https://www.khanacademy.org/science/class-7-science/x0c8b40bd4b242f0b:forces-and-machine/x0c8b40bd4b242f0b:uses-and-disadvantages-of-friction/e/uses-and-disadvantages-of-friction 2026-03-31T02:49:16.891210422Z Uses and Disadvantages of Friction Let's solve some questions on uses and disadvantages of friction Vibhor Pandey exercise