Question

Answer these multiple choice questions about the forces, motions, and momenta in the Stranded on Ice problem. In that problem, the man is assumed to throw the book in the horizontal direction. (a) During the throw, which is stronger force, the force on the book by the man or the force on the man by the book? The force on the man by the book is stronger. The two forces are equally strong by Newton's Third Law. The two forces are equally strong by Newton's First Law. The force on the book by the man is obviously stronger. (b) Suppose the man wants to move towards the East (that being the direction of the nearest shore). In what direction must he throw the book? Towards the South. Towards the East. It doesn't matter in what direction he throws the book, as long as he throws it horizontally. Towards the North. Towards the West. (c) In this experiment with man and book, some value of momentum is a constant. Which statement accurately describes that constant value of momentum? The momentum of the man combined with the momentum of the book (by "adding the arrows") produces a constant value in this experiment. Only the momentum of the man is constant in this experiment. Only the momentum of the book is constant in this experiment. Both the momentum of the man and the momentum of the book are constant in this experiment. (d) Which statement accurately expresses the meaning of the principle of Conservation of Momentum for the Stranded on Ice problem? No matter how the man and book are moving before the throw, after the throw the momentum of the man and the momentum of the book will be equally large. No matter how the man and book are moving before the throw, the momentum of the man combined with the momentum of the book (i.e. the combination of the two momenta) will be the same both before and after the throw. The two statements are logically equivalent, therefore they both express accurately the meaning of the principle of Conservation of Momentum.

Answer 1

a) The two forces are equally strong by Newton's Third Law.

According to third law, every action has equal and apposite reaction.

b)Towards the West

By throwing towards the west the COM remains at the previous spot and man will move in apposite direction.

c)Both the momentum of the man and the momentum of the book are constant in this experiment.

d) No matter how the man and book are moving before the throw, the momentum of the man combined with the momentum of the book (i.e. the combination of the two momenta) will be the same both before and after the throw.