This preview shows page 1. Sign up to view the full content.
Unformatted text preview: value tells us that our initial assumption about the direction of f is incorrect in this case. Thus, the answer is: f s = 32 N up. (f) In this case, P = 18 N downward. The above equation (but with P replaced with P ) with the same assumptions as in part (a), leads to f = (18 22) N = 40 N, which is larger (in absolute value) than f s , max ,  invalidating our assumptions. Therefore, we take f = f k and a 0 in the above equation; if we wished to find the value of a we would find it to be negative, as we should expect. The answer is: f k = 23 N up. (g) The block moves up the wall in case (d) where a > 0. (h) The block moves down the wall in case (f) where a < 0. (i) The frictional force f s is directed down in cases (a), (c) and (d). 100. Analysis of forces in the horizontal direction (where there can be no acceleration) leads to the conclusion that F = F N ; the magnitude of the normal force is 60 N. The maximum possible static friction force is therefore...
View
Full
Document
This note was uploaded on 05/17/2011 for the course PHY 2049 taught by Professor Any during the Spring '08 term at University of Florida.
 Spring '08
 Any
 Physics, Acceleration, Force, Friction

Click to edit the document details