Newton’s Second Law

But First We Need to Know About Mass

Mass The quantity of matter in an object. It is also the measure of the inertia The resistance of an object in response to an effort to start it, stop it, or change its state of motion in any way

Weight Just the force upon an object due to gravity Dependent on the force of gravity Weight = mg Where g is the constant of proportionality and has the value 9.8N/kg or 9.8m/s2

So on the moon… Is your mass the same? Is your weight the same?

An anvil in outer space may be weightless, but it is not massless

An astronaut in space would find that the weightless anvil just as difficult to shake as on Earth This is due to its mass (and inertia)

Mass Resists Acceleration If you push your friend on a skateboard he/she will accelerate If you push an elephant on a skateboard, the acceleration is much less The amount of acceleration depends not only on the force, but the mass

Mass Resists Acceleration The same force applied to twice the mass produces half the acceleration So we say, for a given force, the acceleration produced is inversely proportional to the mass Acceleration ~ 1/mass

Hey Guess What I Found! NFL Physics

Newton’s Second Law of Motion The acceleration of an object is directly proportional to the net force acting on the object, is in the direction of the net force, and is inversely proportional to the mass of the object

The way your book wants you to know the equation for Newton’s Second Law Acceleration = net force/mass a=Fnet/m

Newton’s Second Law Equation

Newton’s Second Law As the force acting upon an object is increased, the acceleration of the object is increased. As the mass of an object is increased, the acceleration of the object is decreased.

How To Do 2nd Law Problems Khan Academy Newton's Second Law

pg. 61 #21-26 pg. 62 Plug and Chug # 6-10