F = ma m is measured in kg a is measured in m/s 2 F is measured in kg m/s 2, called a Newton (N)
Acts at a distance (gravitational field) Force due to Gravity = Weight Acceleration due to Gravity = Constant g = 9.8 m/s 2
Contact Force Acts perpendicular to the surface
Contact force Acts parallel to the surface Acts opposite the direction of motion
Contact force Acts opposite the direction the spring is stretched or compressed Proportional to stiffness of spring and how much it is stretched or compressed
Contact force Force exerted by a string or rope Always acts along the string or rope Equal on both ends of the string or rope* * Unless you have a pulley with mass, like in AP Physics