Physics
posted by Help .
Rubber Band
A 156 g hockey puck is attached to a rubber band and rotated with an angular speed of 9.8 rad/s on frictionless horizontal ice. It takes a force of 1.12 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
.154 OK
(b) How much energy do you need to start the stone from rest and rotate as in part (a) with an angular speed of 9.8 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

centripetal force= masspuck*w^2*r
a) stretch= centripetal force/1.12cm
b) total energy= 1/2 mass*w^2*r^2+1/2 (1.12/cm)*stretch^2
Respond to this Question
Similar Questions

Physics
When the rubber band in a slingshot is stretched, it obeys Hooke's law. Suppose that the "spring constant" for the rubber band is k = 53 N/m. When the rubber band is pulled back with a force of 7.3 N, how far does it stretch? 
Physics
0.17 kg point mass moving on a frictionless horizontal surface is attached to a rubber band whose other end is fixed at point P. The rubber band exerts a force F = bx toward P, where x is the length of the rubber band and b is an unknown … 
Physics
A 0.18 kg point mass moving on a frictionless horizontal surface is attached to a rubber band whose other end is fixed at point P. The rubber band exerts a force F = bx toward P, where x is the length of the rubber band and b is an … 
Physics
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.  … 
Physics
I need help with part b... I found in part a that delta L is .29568m and I think I might be doing something wrong with the units because I can't get the right answer. A 156 g hockey puck is attached to a rubber band and rotated with … 
physics
The type of rubber band used inside some baseballs and golf balls obeys Hooke's law over a wide range of elongation of the band. A segment of this material has an unstretched length l = 1.50 m and a mass m = 5.6 g. When a force F = … 
Physics
One can work out by either lifting weights or using a tension band, which is like a big rubber band. If we model the rubber band as a big spring with spring constant 400 N/M how far in meters must I stretch the the band so it applies … 
Physics
A force of 2N will stretch a rubber band 2 cm. Assuming that Hooke's law applies, how far will a 4N force stretch the rubber band? 
Physics
When the rubber band in a slingshot is stretched, it obeys Hooke's law. Suppose that the "spring constant" for the rubber band is k = 44.2 N/m. When the rubber band is pulled back with a force of 9.38 N, how far does it stretch? 
physics
A force of 2Newtons will stretch a rubber band 2/100 meters. Assuming that Hooke’s Law applies, how far with a force of 4Newtons stretch the rubber band?