Question

A rocket obeys the principles of recoil. However, it is much more difficult to apply Newton's second law to a rocket because

Multiple Choice

• Newton's three laws do not apply in outer space.

• there is actually sideways momentum, because a rocket motor is just a well-controlled explosion.

• the rocket pushes against air but the air is a fluid.

• as the rocket motor fires the total mass of the rocket changes.

A box is pushed across a rough horizontal floor by a force acting parallel to the floor in the direction of motion. A force providing no impulse during the motion is

Multiple Choice

• gravity.

• friction.

• the applied force.

• None of these choices are correct

Suppose two boys are trapped on the ice atop a frozen pond, and that the ice is completely frictionless. The boys are initially at rest, but they do have a baseball. They begin to play catch with the ball. Which of these is true?

Multiple Choice

• The boys only move while the ball is in the air

• They will be stuck on the ice until rescued

• The more times they throw and catch the ball, the faster they will get to shore

• If after a few throws the ball is not caught and rolls away, the boys will be stuck on the ice

Please correctly answer these questions. Thank you!

Answer 1