Chapter 13 Forces and Motion
Gravity • Force of attraction • Dependent upon the masses of each object
Mass vs Weight • Mass • Amount of matter in an object • Does not change in the universe • Measured in N -- newtons • Weight • Measure of gravitational force • Varies • Measured in kg or pounds
Law of Universal Gravitation • All objects in the universe attract each other through gravitational force • Depends upon • Mass • Distance
Orbital Motion • Horizontal movement • Vertical movement
Newton’s First Law • An object at rest remains at rest, and an object in motion remains in motion at constant speed and in a straight line unless acted on by an unbalanced force.
Newton’s Second Law • The acceleration of an object depends on the mass of the object and the amount of force applied.
Newton’s Third Law • Whenever one object exerts a force on a second object, the second object exerts an equal and opposite force on the first.
Additional Terms to Know • Inertia • Terminal velocity • Free fall • Vacuum • Centripetal force