just need someone to double check

Melchior25

Could anyone please double check my answers to each of the following statements. Thanks

1. The problem statement, all variables and given/known data

Determine which of the following moving objects obey the equations of projectile motion.

True A stone is thrown under water.
True A ball is thrown in an arbitrary direction.
True A jet airplane crosses the sky with its engines thrusting the plane forward.
True A rocket moves through the sky after its engines have failed.
False A rocket leaves the launch pad.

PhanthomJay

Not all your answers are correct, even when air resistance is neglected (which should have been stated in the problem). Hint: There is only one force acting on an object in ideal projectile motion problems. What is that force? How does it affect your answers?