Physics: Motion, Newton's Laws, Gravity, and Satellites

What is motion?

Motion is the change in position of an object over time.

What is the formula for velocity?

Velocity = Distance / Time. Be able to calculate any of the three variables if given the other two.

What is acceleration and what are its units?

Acceleration is the rate of change of velocity, typically measured in meters per second squared (m/s²).

What is inertia and who first described it?

Inertia is the resistance of an object to change its state of motion, first described by Sir Isaac Newton. It is related to acceleration as more mass means more inertia, requiring more force to change its motion.

List Newton's three laws of motion in order.

1. An object at rest stays at rest, and an object in motion stays in motion unless acted upon by a force. 2. F = ma (Force equals mass times acceleration). 3. For every action, there is an equal and opposite reaction.

What is the difference between mass and weight?

Mass is the amount of matter in an object and does not change with location, while weight is the force of gravity acting on that mass and can change based on location.

Do falling objects have the same acceleration?

Yes, all objects in free fall near the Earth's surface experience the same acceleration due to gravity, approximately 9.81 m/s², regardless of their mass.

What is Newton's second law of motion?

Newton's second law states that Force = Mass x Acceleration (F = ma). Force is measured in newtons (N).

What is the acceleration caused by gravity on the surface of the Earth?

The acceleration due to gravity on Earth is approximately 9.81 m/s². Weight is measured in newtons (N).

Why don't all objects fall at exactly the same rate in the real world?

Objects may fall at different rates due to air resistance and other forces. Terminal velocity is the constant speed an object reaches when the force of gravity is balanced by air resistance.

How does Newton's third law of motion apply to a bouncing ball?

Newton's third law states that for every action, there is an equal and opposite reaction, which explains how the ball exerts a force on the ground and the ground exerts an equal force back, causing the ball to bounce.

When do Newton's laws not work?

Newton's laws do not apply at very high speeds (close to the speed of light) or at very small scales (quantum level). They are still taught because they accurately describe motion in most everyday situations.

What is remarkable about Newton's Universal Law of Gravitation?

It is called a 'universal' law because it applies to all objects with mass, regardless of their size or distance apart. The force of gravity between two objects depends on their masses and the distance between them.

What is Newton's cannon and what are the possible trajectories?

Newton's cannon is a thought experiment illustrating how a cannonball fired at different speeds can achieve various trajectories: it can fall to the ground, travel in a circular orbit, or escape Earth's gravity.

What is a satellite and why doesn't it crash to Earth?

A satellite is an object that orbits a planet. It doesn't crash to Earth because it is in free fall, moving forward fast enough that the curvature of its path matches the curvature of the Earth.