1.

Derive an expression for the acceleartion of the bodysliding down a frictionless surface

Answer»

Solution :Whenan objectof massmslideson africtionalsurfaceinclinedat anangle `theta` as shownin the figurethe forcesactingonitdecides theaccelerationof THEOBJECT(b)speedof theobject when it reachesthe bottom .

The forceactingon theobject is
(i)Downwardgravitational force (mg)
(II) Normalforceperpendicularto inclinedsurface (N)
theblockis assumedto be apointmass[Inorder to drawthe freebodydiagram in figure(a)].Sincethe motionis on theinclinedsurfacethecoordinatesystemparallelto tehinclinedsurfaceis chosenas shown in thefigure (b)It isnotedthat theanglemadebythe gravitationalforcewith theperpendicularto the surfacesi EQUALTO theangleof inclination `theta` as shown inin figure
`-mg cos theta hat(j)+ N hat(j) = 0`(No acceleration )
Bycomparingthecomponentson bothsidesN- mg cos `theta = 0`
`N= mg cos theta`
Themagnitude of normalforce(N)exertedby tghesurfaceis EQUIVALENTTO mgcos `theta` . Theobjectslidesalongthe x direction .
Bycomparingthe componentson bothsideswe canequate
`mg sin theta= ma `
Theaccelerationof theslindingobjectis


Notethat theacceleratindependson theangleinclination `theta`


Discussion

No Comment Found