home > q&a board > mechanical engineering > topic: momentum????

Q BgQuestion:

Scholar
Karma Points: 200
Respect (92%):
posted by  Daffy on 7/16/2008 5:30:23 PM  |  status: Closed  

Momentum????

Course Textbook Chapter Problem
Classical Mechanics Engineering Mechanics Statics and Dynamics Fifth Edition 16 16.64
Question Details:
 
Ball A travels to the right with velocity vA.  The impact of A with B is perfectly elastic  (e = 1).  B and C are connected by a spring.
What is the maximum compressive force in the spring as a result of the impact?
I have calculated that the velocities of B and C immediately following impact as:
vB = vA and vC = 0.
I also know that the velocity of the unit of B-C is .
I don't know where to go from here.  Any help is greatly appreciated.
Bonus Point Alert! Earn +4 additional karma points for helping this annual member.

AAnswers:

Answer Question
Oracle
Karma Points: 32,717
posted by zsm28 on 7/18/2008 3:02:32 AM  |  status: Live
Asker's Rating: Somewhat Helpful   
Response Details:
Before compression, the kinetic energy of B-C system is mvA2/2.
when the spring has a maximum compression x, B and C has same speed vA/2, the total kinetic energy = 2*m(vA/2)2/2 =  mvA2/4
so the potential energy on the spring = mvA2/2 - mvA2/4 = mvA2/4
which equals kx2/2
so x =
the maximum compression force = kx = √(mkvA2/2)
Answer Question
Ask New Question

Join Cramster's Community

Cramster.com brings together students, educators and subject enthusiasts in an online study community. With around-the-clock expert help and a community of over 100,000 knowledgeable members, you can find the help you need, whenever you need it. Join for free today » How Cramster is different than tutoring »

Need Help In

Useful Links