Download 12314 Motion p.36 42 Gravity All objects accelerate toward Earth at

12­3­14 Motion p.36 ­42 Gravity All objects accelerate toward Earth at a rate of 9.8 m/s/s Every second an object is falling faster and farther. What is the penny’s velocity after it has fallen for 2 seconds? 9.8 x 2 = 19.6 m/s downward The penny hits the ground in 4.5 seconds. What is its final velocity? air resistance Occurs between the surface of the falling object and the air that surrounds it. The amount of air resistance acting on an object depends on the shape and size of the object. terminal velocity As an object falls, the upward force of air resistance continues to increase until it exactly matches the downward force of gravity. When this happens the net force is zero and objects stop accelerating. The object then falls at a constant velocity. A parachute when opened. Free fall only occurs if gravity is pulling it down and no other forces are acting on it. Projectile Motion The curve path an object follows when thrown or propelled near the surface of the Earth. Two components ­ horizontal and vertical Draw and Label Figure 9