Newton’s Second Law of

Motion

Chapter 3Section 1

Force, Mass, & Acceleration

• How does force cause motion to change? • What is the difference between throwing a

baseball and tossing one gently?• In both examples they start at rest. • One has a faster velocity than the other. • Which one has a greater acceleration, the

baseball thrown or the baseball gently tossed?

Force, Mass, & Acceleration

• The greater the force applied to an object, the greater the acceleration will be.

• AKA – the harder the baseball is thrown the faster it will accelerate.

Force & Mass

• If you throw a cotton ball and a baseball as hard as you can, why don’t they have the same speed?

• Because of their different masses.• The acceleration of an object depends on

its mass as well as the force applied to it.• Force, mass, and acceleration are all

connected. • Newton’s Second Law of motion

describes this relationship!

Newton’s Second Law of Motion

• Remember – net force is when more than one force is applied to an object.

• Newton’s Second Law of Motion states:

The net force acting on an object causes the object to accelerate in the direction of the net force.

Newton’s Second Law of Motion

• Another words…• How much an object accelerates

depends on the mass of the object and how much force is applied to it.

• The equation for this is:Force = mass x

accelerationF=ma

Newton’s Second Law of Motion

• Force is measured in Newtons

• Force = mass x acceleration• 1 Newton = kg x m/s2

Newton’s Second Law of Motion

• If a baseball is thrown at 150 m/s2 and it’s mass is .50 kg what force is necessary to change its direction?

• a = 150 m/s2

• m = .50 kg• F = ?• F = ma• F = (.50 kg)(150 m/s2)• F = 75 kg m = 75 N s2