Science 7 Notes 24 Gravity Describe the effect of Surface Area air friction and surface

Air Resistance area on a falling object.

Free Fall Think about it… Calculate the acceleration of a falling object. Which object will fall faster, a golf ball or a piece of paper?

What factors on Earth, affect the Newton’s Hypotheses: rate at which an object falls? There is a force that makes all objects move toward each other and it is called gravity

Explain how force of attraction that exists between all objects in the Universe. satellites are able Gravity - to orbit the Earth without floating • Gravity depends on mass and distance, so an object close to earth’s off into space large mass will be forced toward it. • That’s also why the smaller mass, Earth is forced into an attractive

Explain how such orbit of the sun objects, as a feather and a Most objects falling through air experience a type of friction called air bowling ball, can hit the ground at resistance. the same time if • Air resistance is not the same for all objects. released from the same starting • The greater the surface area of the object the greater the air resistance. point simultaneously For example, a man will fall faster without a parachute but slower with a

parachute

At what rate would all objects Free Fall fall in a vacuum  An object is in free fall when the only force acting on the object is (with no air gravity. friction)?  Free-falling objects do not encounter air resistance.

Calculating Free Fall Acceleration

All objects in free fall accelerate at the same rate – 9.8 m/s² - regardless of their mass.