https://www.khanacademy.org/science/ap-college-physics-1/xf557a762645cccc5:force-and-translational-dynamics/xf557a762645cccc5:gravitational-force/v/gravitational-forces-and-fields 2025-10-06T15:00:50.153987624Z Gravitational forces and fields Newton’s law of universal gravitation describes the gravitational forces two objects exert on each other. The gravitational force is always attractive and is exerted along the line connecting the two objects’ centers of mass. The gravitational field created by an object at a point in space is the gravitational force exerted on another test object at that location, divided by the mass of the test object. If the gravitational force is the only force exerted on an object, the observed acceleration of the object (in m/s^2) is numerically equal to the magnitude of the gravitational field strength (in N/kg) at that location. Mahesh Shenoy video https://cdn.kastatic.org/ka_thumbnails_cache/3d2b9d1b-161f-45a9-a497-effe8b9f3593_1280_720_base.png Gravitational forces and fields Newton’s law of universal gravitation describes the gravitational forces two objects exert on each other. The gravitational force is always attractive and is exerted along the line connecting the two objects’ centers of mass. The gravitational field created by an object at a point in space is the gravitational force exerted on another test object at that location, divided by the mass of the test object. If the gravitational force is the only force exerted on an object, the observed acceleration of the object (in m/s^2) is numerically equal to the magnitude of the gravitational field strength (in N/kg) at that location. https://cdn.kastatic.org/ka-youtube-converted/CJV7RZNCN28.mp4/CJV7RZNCN28.mp4 735 Gravitational field strength: calculation and field line analysis https://www.khanacademy.org/science/ap-college-physics-1/xf557a762645cccc5:force-and-translational-dynamics/xf557a762645cccc5:gravitational-force/e/gravitational-forces 2025-11-17T20:10:48.107689924Z Gravitational force Check your understanding of gravitational forces and how to calculate them using the universal law of gravitation in this set of free practice questions. exercise https://www.khanacademy.org/science/ap-college-physics-1/xf557a762645cccc5:force-and-translational-dynamics/xf557a762645cccc5:gravitational-force/v/weight-apparent-weight-and-weightlessness 2025-10-06T15:00:50.153987624Z Weight, apparent weight, and weightlessness The gravitational force exerted by an astronomical body on a relatively small nearby object is called weight. The magnitude of the apparent weight of an object is the magnitude of the normal force exerted on the object. If the system is accelerating vertically, the apparent weight of the object is not equal to the magnitude of the gravitational force exerted on the object. A system appears weightless when there are no forces exerted on the system, or when the force of gravity is the only force exerted on the system. Mahesh Shenoy video https://cdn.kastatic.org/ka_thumbnails_cache/9a25deb7-ba6c-4d1a-acce-0653b0038687_1280_720_base.png Weight, apparent weight, and weightlessness The gravitational force exerted by an astronomical body on a relatively small nearby object is called weight. The magnitude of the apparent weight of an object is the magnitude of the normal force exerted on the object. If the system is accelerating vertically, the apparent weight of the object is not equal to the magnitude of the gravitational force exerted on the object. A system appears weightless when there are no forces exerted on the system, or when the force of gravity is the only force exerted on the system. https://cdn.kastatic.org/ka-youtube-converted/tVsYgAM8MV4.mp4/tVsYgAM8MV4.mp4 750 Gravitational field strength: calculation and field line analysis https://www.khanacademy.org/science/in-in-class11th-physics/in-in-phy-gravitation/in-in-gravity-newtonian/e/newton-s-law-of-gravity-ap1 2026-03-12T00:50:35.110583553Z Gravitational field strength Predict how gravitational field strength changes with radius and mass. April Russell exercise https://www.khanacademy.org/science/ap-college-physics-1/xf557a762645cccc5:force-and-translational-dynamics/xf557a762645cccc5:gravitational-force/v/inertial-mass-vs-gravitational-mass 2024-11-06T15:51:57.252510189Z Inertial and gravitational mass The inertial and gravitational mass of an object have the same value, but they describe two different things about an object. Learn how to distinguish between inertial and gravitational mass and measure each independently of each other. David SantoPietro video https://cdn.kastatic.org/ka_thumbnails_cache/6fd7357a-14b7-49f2-9d32-80ae149ddee0_1280_720_base.png Inertial and gravitational mass The inertial and gravitational mass of an object have the same value, but they describe two different things about an object. Learn how to distinguish between inertial and gravitational mass and measure each independently of each other. https://cdn.kastatic.org/ka-youtube-converted/Ws3yB3QsKY4.mp4/Ws3yB3QsKY4.mp4 492 Gravitational field strength: calculation and field line analysis https://www.khanacademy.org/science/in-in-class11th-physics/in-in-phy-gravitation/in-in-gravity-newtonian/v/viewing-g-as-the-value-of-earth-s-gravitational-field-near-the-surface 2024-10-31T14:33:34.523193904Z The concept of gravitational field There are two ways to interpret the constant g for Earth. The first interpretation is as the magnitude of the acceleration due to gravity of an object in free fall near Earth's surface. The second interpretation is as the magnitude of the gravitational field at Earth's surface, which can be used to calculate the force of gravity on an object. The magnitude of the gravitational field created by a body at a point in space is equal to the ratio of the gravitational force exerted by the body on an object located at that point in the body's field, divided by the mass of the object. In other words, the gravitational field is the force per unit mass that the body will exert on an object. Sal Khan video https://cdn.kastatic.org/googleusercontent/6AzS1wICHIcbMCTQAzWv545ysTVZsa9H0MqQWrExSGKlnKiXVj89y3HqcRo7LmlD2akZiBMdIBXQg6hPKEi2OmnK The concept of gravitational field There are two ways to interpret the constant g for Earth. The first interpretation is as the magnitude of the acceleration due to gravity of an object in free fall near Earth's surface. The second interpretation is as the magnitude of the gravitational field at Earth's surface, which can be used to calculate the force of gravity on an object. The magnitude of the gravitational field created by a body at a point in space is equal to the ratio of the gravitational force exerted by the body on an object located at that point in the body's field, divided by the mass of the object. In other words, the gravitational field is the force per unit mass that the body will exert on an object. https://cdn.kastatic.org/ka-youtube-converted/1E3Z_R5AHdg.mp4/1E3Z_R5AHdg.mp4 451 Gravitational field strength: calculation and field line analysis