Physics 30: Momentum & Impulse
Momentum
● Inertia: Property of an object that resists acceleration. Inertia is most closely related to
mass and is related to Newton’s First Law(Law of Inertia).
● Conserved: To protect from loss/depletion.
● Momentum is the product of mass and velocity.
● Vector quantities have direction and magnitude(size).
● Scalar quantities have magnitude only.
● Direction is important in all momentum calculations.
● Momentum is proportional to mass & velocity. Increase in mass or velocity = increase in
momentum.
● If mass or velocity is doubled then momentum will be doubled so the new momentum
will be twice the original momentum.
Impulse
● Impulse = change in momentum
● The impulse equation can only be used when the net force is constant.
● Impulse & momentum are vector quantities.
● A force is applied to an object to change its momentum.
● Up, north, right & east are positive; down, south, west, and left are negative.
● If you apply an impulse on an object; the object will experience a change in momentum.
● Impulse can also be a net force applied to an object times time.
● Newton’s Second Law: Net Force= mass x acceleration.
● Net Force is also equal to change of impulse over time.
● Acceleration: Change in velocity over time.
● Larger net force = smaller time if mass & velocity are constant. Swift execution occurs
when a large net force is applied over a small period of time.
● Large impulse requires a large net force and a small amount of time or a small net force
and a large amount of time.
● Newton’s second law in terms of momentum is more useful than Newton’s second law in
terms of acceleration because you can apply it to situations where mass, velocity, or both
the mass and velocity are changing.
● Newton’s Third Law: For every action, there is an equal and opposite reaction.
Force as a Function of Time Graphs
● The area under the net force-time graph = impulse.
Conservation of Momentum
● Energy can be lost to sound, light, or heat.
● Work is done by friction. Work = change in energy.
Momentum
● Inertia: Property of an object that resists acceleration. Inertia is most closely related to
mass and is related to Newton’s First Law(Law of Inertia).
● Conserved: To protect from loss/depletion.
● Momentum is the product of mass and velocity.
● Vector quantities have direction and magnitude(size).
● Scalar quantities have magnitude only.
● Direction is important in all momentum calculations.
● Momentum is proportional to mass & velocity. Increase in mass or velocity = increase in
momentum.
● If mass or velocity is doubled then momentum will be doubled so the new momentum
will be twice the original momentum.
Impulse
● Impulse = change in momentum
● The impulse equation can only be used when the net force is constant.
● Impulse & momentum are vector quantities.
● A force is applied to an object to change its momentum.
● Up, north, right & east are positive; down, south, west, and left are negative.
● If you apply an impulse on an object; the object will experience a change in momentum.
● Impulse can also be a net force applied to an object times time.
● Newton’s Second Law: Net Force= mass x acceleration.
● Net Force is also equal to change of impulse over time.
● Acceleration: Change in velocity over time.
● Larger net force = smaller time if mass & velocity are constant. Swift execution occurs
when a large net force is applied over a small period of time.
● Large impulse requires a large net force and a small amount of time or a small net force
and a large amount of time.
● Newton’s second law in terms of momentum is more useful than Newton’s second law in
terms of acceleration because you can apply it to situations where mass, velocity, or both
the mass and velocity are changing.
● Newton’s Third Law: For every action, there is an equal and opposite reaction.
Force as a Function of Time Graphs
● The area under the net force-time graph = impulse.
Conservation of Momentum
● Energy can be lost to sound, light, or heat.
● Work is done by friction. Work = change in energy.
