Transcript Chapter 10 Section 4

Chapter 10 Section 4
Newton’s Third Law
Newton’s Third Law of Motion
• Newton’s third law of motion states that if
one object exerts a force on another object,
then the second object exerts a force of
equal strength in the opposite direction on
the first object.
• Action reaction Pairs When you jump you push on the
ground with your feet, action force. The ground pushes back on your
feet with equal and opposite force.
• Detecting Motion when the earth’s gravity pulls on an object,
you cannot detect the equal and opposite reaction of Earth
• Do action-reaction forces cancel? NEVER Because
they are acting on different objects.
Momentum
• Momentum is a property of a moving
object that depends on object’s mass and
velocity.
• You can calculate the momentum of a
moving object by multiplying the object’s
mass and velocity
Momentum=Mass X Velocity
The more momentum a moving object has,
harder it is to change its velocity.
Conservation of Momentum
• When a moving object hits another object, some
or all of the momentum of the first object is
transferred to the other object.
• Law of conservation of momentum states that
momentum of any group of objects remains the
same, or conserved, unless outside forces act
on the object.
Collision with two moving objects The momentum of the first object
decreases, and the momentum of the second object increases.
Collision with one moving object All of the momentum of the moving
object is transferred to the other object.
Collision with connected objects The momentum of both objects will
be the same. (Page 398)