6/7/2015 MasteringPhysics:AssignmentWeek5

https://session.masteringphysics.com/myct/itemView?view=print&assignmentProblemID=48433354 1/3

Item9

LearningGoal:

Tounderstandthevectornatureofmomentuminthecaseinwhichtwoobjectscollideandsticktogether.

Inthisproblemwewillconsideracollisionoftwomovingobjectssuchthatafterthecollision,theobjectssticktogetherandtraveloffasasingleunit.Thecollisionisthereforecompletelyinelastic.

Youhaveprobablylearnedthat"momentumisconserved"inaninelasticcollision.Buthowdoesthisfacthelpyoutosolvecollisionproblems?Thefollowingquestionsshouldhelpyoutoclarifythemeaningandimplicationsofthestatement"momentumisconserved."

PartA

Whatphysicalquantitiesareconservedinthiscollision?

ANSWER:

PartB

Twocarsofequalmasscollideinelasticallyandsticktogetherafterthecollision.Beforethecollision,theirspeedsare and .Whatisthespeedofthetwocarsystemafterthecollision?

Youdidnotopenhintsforthispart.

ANSWER:

themagnitudeofthemomentumonlythenetmomentum(consideredasavector)onlythemomentumofeachobjectconsideredindividually

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6/7/2015 MasteringPhysics:AssignmentWeek5

https://session.masteringphysics.com/myct/itemView?view=print&assignmentProblemID=48433354 2/3

PartC

Twocarscollideinelasticallyandsticktogetherafterthecollision.Beforethecollision,themagnitudesoftheirmomentaare and .Afterthecollision,whatisthemagnitudeoftheircombinedmomentum?

Youdidnotopenhintsforthispart.

ANSWER:

PartD

Twocarscollideinelasticallyandsticktogetherafterthecollision.Beforethecollision,theirmomentaare and .Afterthecollision,theircombined

Theanswerdependsonthedirectionsinwhichthecarsweremovingbeforethecollision.

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Theanswerdependsonthedirectionsinwhichthecarsweremovingbeforethecollision.

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6/7/2015 MasteringPhysics:AssignmentWeek5

https://session.masteringphysics.com/myct/itemView?view=print&assignmentProblemID=48433354 3/3

momentumis .Ofwhatcanonebecertain?

Youdidnotopenhintsforthispart.

ANSWER:

PartE

Twocarscollideinelasticallyandsticktogetherafterthecollision.Beforethecollision,themagnitudesoftheirmomentaare and .Afterthecollision,themagnitudeoftheircombinedmomentumis .Ofwhatcanonebecertain?

Youdidnotopenhintsforthispart.

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