Final answer:
The statement regarding the pen is true as it becomes a projectile when thrown, moving in two-dimensional projectile motion. The rocket statement is also true, following Newton's first law, as it would travel in a straight line until another force acts upon it.
Step-by-step explanation:
The statement that 'The pen became a projectile when it was thrown across the room' can be considered true because projectile motion is defined as the motion of an object thrown or projected into the air, subject only to the acceleration due to gravity. In this case, the pen, once released, follows a trajectory determined by the forces acting on it, which includes gravity and the initial force imparted by the throw. The path of the pen, neglecting air resistance, is an example of two-dimensional projectile motion, where the pen moves horizontally while simultaneously being pulled down by gravity. The complexity of projectile motion has many practical applications in both physics and engineering, such as the motion of sports balls or meteors entering the Earth's atmosphere.
Regarding the statement 'A rocket is launched into space and escapes Earth's gravitational pull. It will continue to travel in a straight line until it is acted on by another force.' we consider Newton's first law of motion, which states that an object in motion will stay in motion with a constant velocity (which can include a state of rest) unless acted upon by a net external force. Therefore, if a rocket indeed escapes Earth's gravitational pull and is not subject to any other forces, it would continue to travel in a straight line, making the statement true.