posted by nicholas .
A spherical comet of mass m and diameter is d, travelling at velocity v enters a cloud of stationary cosmic meteoroids (small rocks). The average density of the cloud is p. When a meteoroid impacts the comet it adheres to its surface. As a result the comet slows down and after traveling t it exits the cloud. How much time in seconds does the comet spend in the cloud? (what is time t?)
change in momentum=added mass*average velocity
volume swept out by comet=PI*(d/2)^2*averageveloccity*time
change in momentum=p*PI*(d/2)^2*averagevelocity*time
change in momentum=mv+(m+massadded)(vf)
To actually solve this you have to know v, and vf, as I see it.