An iceboat is traveling in a circle on the ice. Halfway around the circle the sail and the steering mechanism fall off the boat. Which statement is correct?
A) The boat will continue traveling in the circle because there is no friction.
B) The boat will continue to travel in the circle because its velocity exerts a force on it.
C) The boat will move off on a line tangent to the circle because there is no force on it.
D) The boat will move off tangent to the circle because there is a force on it perpendicular to the boat directed to the outside of the circle.
E) The boat will move off to the outside perpendicular to the tangent line since a force directed to the outside of the circle always acts on the boat.

Question

Quizplus · Accepted Answer

When the sail and steering mechanism fall off the boat, there is no longer any force acting on the boat to keep it traveling in a circle. The boat will therefore move off on a line tangent to the circle, since there is no force to change its direction. The absence of friction doesn't affect the boat's motion in this case because friction is not the only force acting on the boat. The boat's velocity does exert a force on it, but this force is in the direction of motion (tangential to the circle) and doesn't affect the boat's direction of travel. The other choices are also incorrect because they don't take into account the fact that there is no longer any force acting on the boat to keep it on a circular path.

An Iceboat Is Traveling in a Circle on the Ice