Title: GR9677.031
Post by: conantee on December 07, 2010, 12:02:06 AM
31. A sphere of mass 
is released from rest in a static viscous medium. In addition to the gravitational force of magnitude 
, the sphere experiences a retarding force of magnitude 
, where 
is the speed of the sphere and 
is a constant. Assume that the buoyant force is negligible. Which of the following statements about the sphere is correct?
(A) Its kinetic energy decreases due to the retarding force.
(B) Its kinetic energy increases to a maximum, then decreases to zero due to the retarding force.
(C) Its speed increases to a maximum, then decreases back to a final terminal speed.
(D) Its speed increases monotonically, approaching a terminal speed that depends on but not .
(E) Its speed increases monotonically, approaching a terminal speed that depends on both and .
is released from rest in a static viscous medium. In addition to the gravitational force of magnitude , the sphere experiences a retarding force of magnitude , where is the speed of the sphere and is a constant. Assume that the buoyant force is negligible. Which of the following statements about the sphere is correct?(A) Its kinetic energy decreases due to the retarding force.
(B) Its kinetic energy increases to a maximum, then decreases to zero due to the retarding force.
(C) Its speed increases to a maximum, then decreases back to a final terminal speed.
(D) Its speed increases monotonically, approaching a terminal speed that depends on
but not .(E) Its speed increases monotonically, approaching a terminal speed that depends on both
and .