Question

Problem 9.25 Correct A 1.5-kg metal cylinder on a table is placed inside a hoop that is forced at the end of a meter stick. The stick can rolate around a vertical axis that is located 20 cm from the cylinder, as shown in (Figure 1). By exerting a force on the stick, you can make the cylinder rotate in a horizontal plane, with the bottom surface of the cylinder sliding on the rough table. The coefficient of kinetic friction between the cylinder and the table is 0.30 Part Determine the work done by the stick on the cylinder during the one full turn around the axis. Express your answer with the appropriate units. Figure ' HA O W. Value J Submit Previous Answers Request Answer X Incorrect; Try Again; 4 attempts remaining Provide Feed

Answer 1

A)
let m = 1.5 kg
mue_k = 0.3
normal force acting on the cyllinder, N = m*g
kinetic friction acting on the cyllinder, fk = N*mue_k

= m*g*mue_k

= 1.5*9.8*0.3

= 4.41 N

let F is the applied force, F*80 = fk*20

F = fk*20/80

= fk/4

= 4.41/4

= 1.10 N <<<<<<<<---------------Answer

B) Wor kdone by hand, W = F*2*pi*r

= 1.10*2*pi*0.8

= 5.53 J <<<<<<<<---------------Answer