Question

Question: -In which of the following situations is the moving object appropriately modeled as a projectile? Choose all correct answers.

(a) A shoe is tossed in an arbitrary direction.

(b) A jet airplane crosses the sky with its engines thrusting the plane forward.

(c) A rocket leaves the launch pad.

(d) A rocket moves through the sky, at much less than the speed of sound, after its fuel has been used up. (e) A diver throws a stone under water.

Short answer

The correct options are (a) and (d).

Step-by-step solution

Step 1:

The motion of a body only under the action of gravitational force, is called projectile motion. A trajectile generally follows a parabolic path, when launched upward from the surface of earth.

Step 2:

Only gravitational force acts on the body in projectile motion; no other force acts on the body. The motion of a body that has a force other than gravitational in it is not projectile motion.

The motion does not account for air resistance.

As the shoe is hurled in any direction, it acquires some initial velocity and is subjected to no other force than gravity. As a result, its motion is projectile motion.

Movement of the rocket through the sky

Only until an additional force counteracts gravity and propels the rocket skyward does the rocket leave the launch pad. As a result, it isn't a projectile motion.

The motion of a rocket at a significantly slower speed after it has consumed all of its fuel, is projectile motion because there is no other force acting on the rocket except gravity. As a result, it's a projectile movement.

Stone has a higher density than water, thus when it is submerged, it is subjected to a frictional force. As a result, its movement is not termed projectile motion.

So, the correct options are (a) and (d).