Question

determine which of the following moving objects obey the equations of projectile motion developed in this chapter. (select all that apply.) a ball is thrown in an arbitrary direction. a jet airplane crosses the sky with its engines thrusting the plane forward. a rocket leaves the launch pad. a rocket moves through the sky after its engines have failed. a stone is thrown under water.

Explanation:

Projectile motion equations apply when the only force acting on an object is gravity. A ball thrown in an arbitrary direction and a rocket moving through the sky after its engines have failed are only under the influence of gravity (neglecting air - resistance in the ideal case). A jet airplane has engine thrust, a rocket leaving the launch pad has thrust from its engines, and a stone thrown underwater is affected by buoyancy and water resistance in addition to gravity.

Answer:

A. A ball is thrown in an arbitrary direction.
D. A rocket moves through the sky after its engines have failed.