A boy on ice skates is atationary on a frozen lake(no friction).He throws a package of mass 5kg at 4m/s horizontally east.the mass of the boy is 60kg.at the instant the package leaves the boy's hand,the boy starts moving.

Question

A boy on ice skates is atationary on a frozen lake(no friction).He throws a package of mass 5kg at 4m/s horizontally east.the mass of the boy is 60kg.at the instant the package leaves the boy's hand,the boy starts moving.
Calculate the magnitude of the velocity of the boy immediately after the package leaves his hand.ignore the effect of the friction

bobpursley · Answer

conservation of momentum. initial momtentum=finalmonentum 0=5*4 East+ 60*V solve for V V= 1/3 (-E) or .333m/s W