5-Momentum-Impulse.pdfnsjshandksndndnnmdjs

Understanding Physics and it's inner topic

1. MOMENTUM &
IMPULSE
PHYSICS FOR ENGINEERS
ENGR. IVAN CLYDE L. SULAY

2. INTRODUCTION
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Inengineeringphysics,momentumandimpulseare
fundamentalconceptsthatprovideapowerfulframeworkfor
analyzingandsolvingproblemsrelatedtoforcesandmotion,
particularlyindynamicsystemsinvolvingcollisions,impacts,
andexplosions.

3. MOMENTUM
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1. Linear Momentum
Linear momentum (p) is a
vector quantity that describes
the "quantity of motion" of an
object. It is a direct measure of
an object's mass in motion.
Definition:The linear
momentum of an object is
defined as the product of its
mass (m) and its velocity (v).
p=mv

4. MOMENTUM
04
Units:The standard SI unit for
momentum is kilogram-meter
per second (kg·m/s).
Vector Nature:As a vector
quantity, momentum has both
magnitude and direction. Its
direction is always the same as
the velocity vector.

5. MOMENTUM
05
A key principle related to
momentum is the Law of
Conservation of Linear
Momentum .
This law states that if the net
external forceacting on a
system is zero, the total linear
momentum of the system
remains constant.
∑p initial =∑p final

6. MOMENTUM
06
This principle is essential for
analyzing collisions, as the total
momentum of the colliding
objects just before the collision
is equal to the total momentum
just after, regardless of the
complexity of the forces
involved during the brief
impact.

7. IMPULSE
07
Impulse (J) is a measure of the
effect of a force acting over a
period of time. It is the cause of a
change in an object's momentum.
Definition: Impulse is defined as the
integral of a force (F) over a time
interval (Δt). For a constant force,
this simplifies to:
Units: The standard SI unit for
impulse is the newton-second (N·s),
which is dimensionally equivalent to
kg·m/s.

8. THE IMPULSE-MOMENTUM THEOREM
The Impulse-Momentum Theorem is a direct consequence
of Newton's second law of motion and provides the
fundamental relationship between impulse and momentum. It
states that the impulse applied to an object is equal to the
change in the object's momentum.
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9. THE IMPULSE-MOMENTUM THEOREM
This theorem is one of the most useful tools for engineers
because it simplifies the analysis of complex dynamic events.
Instead of tracking forces and accelerations, which can be
highly variable during an impact, an engineer can simply
measure the change in momentum to determine the average
force or the duration of the impact.
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10. REAL-LIFE ENGINEERING
APPLICATIONS
1.AutomotiveSafetyEngineering:
AirbagsandCrumpleZones :Theseareprime
examplesoftheimpulse-momentumtheorem.
Inacollision,thegoalistobringthepassenger's
momentumtozero.Thechangeinmomentum(Δp)is
constant.Bydesigningairbagsandcrumplezonesto
increasethecollisiontime(Δt),engineerscan
significantlyreducetheaverageforce(Favg )exertedon
theoccupants,thus preventingsevereinjury .
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11. AIRBAGS AND CRUMPLE ZONES
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12. REAL-LIFE ENGINEERING
APPLICATIONS
2.CivilandStructuralEngineering:
ArrestorBeds: Onsteepgrades,runawaytruck
rampsareasafetyfeaturedesignedtostopavehicle
withbrakefailure.
Theserampsarefilledwithsandorgravel,which
providesalargeandconsistentretardingforceovera
longdistance.Byincreasingthestoppingtime(Δt),the
averageforcerequiredtostopthetruckisreduced,
preventingacatastrophiccrash .
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13. REAL-LIFE ENGINEERING
APPLICATIONS
3.AerospaceandMechanicalEngineering:
RocketPropulsion: Arocketworksbyexpellinga
high-velocitystreamofgas.
Theforcethatpropelstherocketforward(thrust)
istheresultoftheimpulsegeneratedbytherapid
changeinmomentumoftheexpelledgas.Asmassis
ejectedbackward,therocketreceivesanequaland
oppositeimpulse,causingitto accelerateforward.
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14. 15
PROBLEM SOLUTION
A1500kgcartravelingat25m/scrashes
intoaconcretebarrierandcomestoa
completestopin0.20seconds.
a)Calculatetheinitialmomentumof
thecar.
b)Calculatetheimpulseonthecar.
c)Calculatetheaverageforceexerted
onthecarduringthecrash.

15. 16
PROBLEM SOLUTION
A20kgrobotarmmovesapartfrom
resttoavelocityof5m/sin0.1seconds.
a)Whatisthechangeinmomentumof
thepart?
b)Whatistheimpulsedeliveredbythe
robotarm?
c)Whatistheaverageforceexertedon
thepart?

16. CONCLUSION!
From the macro-scale of a runaway truck ramp to the precise dynamics of a rocket
launch, the principles of momentum and impulse enable engineers to design safer,
more efficient, and more effective solutions to some of the most challenging
problems in modern technology.
Their application demonstrates a deep understanding of how forces affect motion
and is a testament to the power of fundamental physics in shaping the world
around us.
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17. THANK YOU
FOR THE
ATTENTION!