Rubber Band?

Question

A 100 g ball is attached to a rubber tube and is spun around in a circle at a rate of one revolution every second. A force of 0.5 N is required to stretch the tube 1.0 cm.
(a) If the original length is L = 1.0 m, what will be the change in length of the rubber tube when the ball is revolving?
(b) How much energy do you expend to bring the ball off the ground to a height of 2.5m and then get it swinging at a rate of one revolution every second? Neglect the mass of the rubber tube.

Answer 1

a )Centripetal force is
Fc= m(V^2/R)
Tangential velocity is
V=wR= 1x 2 pi R
we have
Fc= m (4 pi ^2 )R

R= L + (.01/.5)Fc

b)E= Pe+ Pe(rubber)
Pe - potential energy
Pe(rubber) - Energy required to streach rubber (2.5 x 2(1)m)

Pe(rubber) = 0.5(k)x^2
k= 0.5 N/.01 m=50 N/m
x= 2.5- 2=.5m
and
Swinging at the rate of 1 rev
Ke=0.5 mV^2
V=2pi (1 rev per sec)R

Answer 2

rubber is a flexible thins.most women r using rubber as a hair band.It is a distroyar thing which it is not good for hair.

Answer 3

(a). 0.0857

(b). 5