Newton knew that the gravitational force on the apple equals the apple’s weight , mg , where g = 9.8 m/ s 2 .
INCREASES with Mass
DECREASES with Distance
W = mg
Gravity and Motion Free Fall Free fall- when gravity is the only force acting on an object (free fall acceleration is directed toward center of earth) The acceleration of gravity ( g ) for objects in free fall at the earth's surface is 9.8 m/s 2 . Galileo found that all things fall at the same rate in the absence of air resistance, regardless of their mass
A stone and a feather will fall at the same speed.
Terminal Velocity : it is reached when the force of air resistance equals the weight of the object
Projectile Motion When an object is thrown into the air, two forces and two motions affect the movement of the object. The object may be thrown horizontally with a certain force, but the vertical force of gravity combines to affect the motion. Slow projectile - shoot a monkey Fast projectile - shoot a monkey