Unit 3: Circular Motion and Gravitation

Uniform circular motion is the motion of an object moving in a circular path at a constant speed.

In Uniform Circular Motion, although the speed may be constant, the velocity is not because the direction is always changing.

Since the velocity is changing in Uniform Circular Motion, there must be acceleration.

Centripetal force is the force that acts on an object moving in a circular path, directed towards the center of the circle.

Centripetal force is responsible for keeping the object moving in a circular path.

Centripetal acceleration is what turns the velocity vectors to keep the object traveling in a circle.

a꜀ = v^2/r

F = mv^2 / r

Examples include a car around a circular track, a satellite orbiting the Earth, and a ball on a string being swung in a circle.

The four fundamental forces in physics are the gravitational force, the electromagnetic force, the weak force, and the strong force.

Gravity dominates at the largest mass and distance scales because its effects are proportional to the mass of the objects involved.

The gravitational force is the force of attraction between two masses.

F = G * (m1 * m2) / r^2

Coulomb's Law describes the attractive or repulsive force between two charged objects.

F = k * (q1 * q2) / r^2

Gravitational acceleration is the acceleration experienced by an object due to the force of gravity.

g = G * M / r^2

On Earth, the value of gravitational acceleration is approximately 9.81 m/s^2.

If an object is in free fall, the gravitational force is the only force being exerted on the object.

g = Gm/r^2