Final answer:
In high school Physics, it's established that motion and forces are governed by laws which help us understand the behavior of objects in motion. For example, a position vs time graph of an object speeding up is not a straight line, but a curve, and kinetic and potential energy of a thrown rock changes inversely during its flight. An object's state of motion in space requires an external force to change, consistent with Newton's First Law.
Step-by-step explanation:
The subject of the question is Physics, particularly related to motion and forces. When dealing with questions of this nature, it is important to have a clear understanding of the basic principles of kinematics and dynamics, which are foundational topics in high school physics.
- Position vs time graph: False. If an object is speeding up, the position vs time graph will be a curve that gets steeper over time due to increasing velocity.
- Average speed vs average velocity: False. Average velocity could be zero if the object returns to its starting position, while average speed tracks the total distance covered over time.
- Kinetic and potential energy: False. When a rock is thrown upwards, its kinetic energy decreases as it ascends and its potential energy increases. As it falls, the reverse occurs.
- Frequency at the speed of sound: False. The frequency does not become infinite; however, a sonic boom may occur if the source moves at or above the speed of sound due to the accumulation of sound waves.
- External force in outer space: True. An external force is required to change the state of motion of an object in space, in accordance with Newton's First Law of Motion.
- Comet's tail and relativistic effects: False. The length of a comet's tail is influenced by solar radiation pressure, not relativistic effects.
- Displacement vs time graphs: True. With constant acceleration, a graph of displacement versus time squared would produce a straight line because it reflects a quadratic relationship.
- Newton's Third Law: True. Walking involves Newton's Third Law, where the ground exerts an equal and opposite force, allowing movement.
- Kepler's laws of planetary motion: True. A satellite does speed up as it approaches its parent body and slows down as it moves away, consistent with Kepler's laws.
- Solar sail propulsion: True. A solar sail craft can indeed be propelled by the momentum transferred from solar wind particles.