Thursday
November 27, 2014

Homework Help: Physics

Posted by Susan on Friday, December 3, 2010 at 2:00pm.

A 156 g hockey puck is attached to a rubber band and rotated with an angular speed of 9.2 rad/s on frictionless horizontal ice. It takes a force of 1.22 N to stretch the rubber band by 1 cm.



--------------------------------------------------------------------------------
(a) If the original length L of the rubber band is 1 m, by how much (in m) will it be stretched by the rotation?
Delta L = m

HELP: The centripetal force has to equal the elastic force.

HELP: The centripetal force is equal to

Fc = mass*length*omega2,

where length is now the stretched length, that is,

length = L + (Delta L).

The elastic force is equal to

Felast = k*(Delta L).

Since the two are equal, you have an equation for Delta L.



--------------------------------------------------------------------------------
(b) How much energy do you need to start the stone from rest and rotate as in part (a) with an angular speed of 9.2 rad/s? Neglect the mass of the rubber band.
Etotal = J

HELP: Add up the kinetic energy and the elastic potential energy.

HELP: Ekin = 1/2*m*v2, with v = length*omega.

Remember again to use the stretched length:

Eelast = 1/2*k*(Delta L)2

Answer this Question

First Name:
School Subject:
Answer:

Related Questions

Physics - Rubber Band A 156 g hockey puck is attached to a rubber band and ...
Physics - I need help with part b... I found in part a that delta L is .29568m ...
Physics - A hockey puck slides along the ice. There is a frictional force ...
Physics - a person pushes on a hockey puck with their stick at an angle so the ...
Physics - A 0.18 kg point mass moving on a frictionless horizontal surface is ...
physics - Hockey Puck A 110 g hockey puck sent sliding over ice is stopped in 13...
Physics - 0.17 kg point mass moving on a frictionless horizontal surface is ...
physics - A hockey puck with mass 0.160kg is at rest on the horizontal, ...
physics - Unless otherwise stated, all objects are located near the Earth's ...
physics - a hockey puck is sliding across frictionless ice at 6m/s. a)what is ...

Search
Members