A spring S of force constant k=100 N/m. is fixed to the base of a 30degree incline.A mass m=50g. is held against the free end of the spring,sothat the spring is compressed by 0.1 metre.If the mass is nowreleased,calculate the distance travelled by the mass up the incline.dontignore friction.i tried using conservation of evergy theorem but i am not getting the solution.howshould i start?

Always keep in mind that first u have to select a system before solving any question. then see if there are only internal forces or not and also those internal forces are conservative or not if there are only internal conservative forces then only u can apply conservation of energy.  If u applied energy conservation in this case then it wud be wrong bcoz friction is non conservative force.

*work energy theoram is always valid. u can apply it in case case.

Approved

Conservation of mechanical energy should not be made use of only if there is friction force doing work. Instead go for work energy theorem.