in the M3 Keith Pledger edexcel textbook, page 66 example 15:
A particle P of mass 0.2kg is attached to one end of a light elastic string of natural length 0.6m and modulus of elasticity 8N. The other end of the string is fixed to a point A on a ceiling. When the particle is hanging in equilibrium the length of the string is Lm.
a)calculate the value of L,
using Hooke's law I obtained L =0.747
The particle is held at A and released from rest. It first comes to instantaneous rest when the length of the string is Km.
b)Use Energy Considerations to calculate the value of K.
Now I know how to use the energy equations to solve the answer, and in side of the page the note to the example says "the question states that you must do this part using conservation of energy"..
Now that is all ok, but I got the message that there may be another way to solve this ==> using the geometrical methods equations
(ie v^2 = w^2 (a^2 - x^2)
I have tried using geometrical methods but have not been able to find the right answer this way. I have got the value w = 200/3.
and using the information from part b, am I right in setting v = 0 in the geometrical methods equation?
Can someone confirm if part b is solvable using geometrical methods ( if it is, could they please show me how?)
Thanks in advance!!