Gravity Physical Science Section 3.2

Gravity All objects have a gravitational attraction for all other objects Law of Gravitation- Any two masses exert an attractive force on each other Attractive force depends on Mass of each object and distance between objects Greater mass = greater attraction

Gravity Closer together= greater attraction Gravity is a long range force The attraction between 2 objects NEVER entirely disappears Force of gravity near Earth’s surface F = m x 9.8 m/s 2 Free Fall- When an object is influenced only by the force of gravity

Gravity Greater mass = greater inertia, so even with more attraction to the earth, objects fall at the same rate Gravity pulls you toward the floor The floor exerts an equal upward force on you, preventing you from falling Weight- gravitational force exerted on an object

Gravity Travel away from earth = increase in distance Increasing distance = decrease in gravitational attraction Weight would decrease. Mass would be the same Astronauts- constantly falling toward the earth at the same rate as the space shuttle

Gravity Projectiles- Objects thrown or shot through the air Horizontal and vertical velocities Horizontal- force that sets object in motion Vertical- gravity Dropping item off a cliff and shooting item off a cliff will result in both items falling in the same amount of time Same vertical distance and pull of gravity

Gravity Acceleration toward center of a circle- centripetal acceleration Centripetal force- A force acting on an object in a direction toward the center of a curve Satellites orbit the Earth because Earth’s gravity exerts a centripetal force on the satellite