Question: Which of the following observers might observe something that appears to violate Newton's first law of motion? Explain why. (1) A person standing still on a street corner (2) A person riding on a roller coaster (3) A passenger on a starship traveling at 0.75c toward the nearby star Alpha Centauri (4) An airplane pilot doing aerobatic loops (5) A hockey player coasting across the ice.

According to Newton’s First Law of motion If a body is at rest it will remains at rest and if a body is in motion it will remains in motion unless it is compelled by any external force.

$\left(1\right)$This person will not observe any violation to Newton’s first law of motion. Since, this person is standing still, there is no motion. Therefore, the person is in inertial reference frame.

$\left(2\right)$This person will not observe any violation to Newton’s first law of motion. As the one can determine the net force acting on roller coaster using Newton’s first law.

$\left(3\right)$This person observe the violation to Newton’s first law of motion. As this person is not moving with constant velocity.

$\left(4\right)$When the airplane is doing aerobatic loops, one can determine the net force acting on pilot using Newton’s first law so this observation obeys newton’s first law.

$\left(5\right)$If the player coasting across the ice, one can determine the net force acting on it using Newton’s First law of motion so this observation follows Newton’s law

Thus, out of all, the observers in situation role="math" localid="1657709890319" $\left(3\right)$may feel that Newton’s first law has been violated.