This preview shows page 1. Sign up to view the full content.
Unformatted text preview: sign!) The x component is negative. The cosine of the angle between the string and the horizontal is cos = x/ (x 2 + h 2 ) Therefore, when the block is at x, the xcomponent of the tension is T x = Tcos = Tx/ (x 2 + h 2 ) At x = 3 m, the T x is T x = Tcos = 303/ (3 2 + 2 2 ) = 25.0 N b) What is the change in the kinetic energy of the cart during the move? According to the workenergy theorem, the change in the kinetic energy of an object is equal to the work done on the object. The definition of work yields K = W = T x dx = [Tx/ (x 2 + h 2 )]dx Changing the variable from x to s = (x 2 + h 2 ) and integrating from x 1 to x 2 , we get K =  Tds = T[ (x 2 2 + h 2 )  (x 1 2 + h 2 )] = 72.7 J...
View
Full
Document
This note was uploaded on 01/25/2011 for the course PHY 2048 taught by Professor Field during the Summer '08 term at University of Florida.
 Summer '08
 Field
 Work

Click to edit the document details