home > q&a board > physics > topic: mass in circular motion

Q BgQuestion:

Scholar
Karma Points: 200
Respect (100%):
posted by  jperk980 on 9/20/2008 8:43:08 PM  |  status: Closed  

Mass in Circular Motion

Course Textbook Chapter Problem
Calculus Based Physics N/A N/A N/A
Question Details:
A mass M of 2.07 kg is attached to the end of a string whose length is 0.450 m. The mass slides without friction on a horizontal surface as indicated in the diagram.

The mass, with a new string, is whirled in a vertical circle of the same radius about a fixed point. Find the magnitude of the tension when the mass is at the top if its speed at the top is 7.53 m/s.
Bonus Point Alert! Earn +4 additional karma points for helping this annual member.

AAnswers:

Answer Question
Oracle
Karma Points: 8,780
posted by booboo123 on 9/21/2008 9:43:38 AM  |  status: Live
Asker's Rating: Lifesaver   
jperk980's comment:
"Thank you!"
Response Details:
At the top, the forces acting toward the center must equal  mv2 / r
these forces are:    gravity pulling down,   and   tension pulling down.
So,     
mg  +   T  =  mv2 / r     
now we can solve for T:
T  =   mv2 / r   -  mg 
=  2.07 * 7.532 / 0.450  -  2.07*9.8  =
=     240.53  newtons
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