Presentation on theme: "Physical Science Mr. Barry. Gravity is a Force Every object in the Universe exerts a force on every other object Gravity: force of attraction between."— Presentation transcript:
Gravity is a Force Every object in the Universe exerts a force on every other object Gravity: force of attraction between two objects Often this force is too slight to notice Can you feel the person next to you pulling on you?
Discovery of Gravity First discovered by Sir Isaac Newton Included in his 3 Laws of Motion (to be covered later) Did he really discover it or was it already there?
Calculating Gravity Gravity depends on: 1. The mass of the objects attracted to each other 2. The distance between the two objects Because everything here on Earth is much smaller than the Earth and is relatively close to the Earth, gravity is considered a constant g = 9.81 m/ s 2
Calculating Force of Gravity Your “force of gravity” is more commonly known as your weight W = mg W = weight (Newtons) m = mass (kg) g = gravity constant ( 9.81 m/s 2, always the same on Earth) Add this to your equation sheet!! This is why weight and mass are not the same thing!!
Gravity = Constant Everything, no matter how massive, has the same gravitational acceleration If the only force on two objects is gravity, they will fall at the same rate Famously discovered by Galileo at the Leaning Tower of Pisa
Vertical Motion Objects accelerate downward because of gravitational force “Free Fall” This means their speed increases the longer they fall