Physics Chapter: Uniform Circular Motion

A unit of angle measurement, where 2π radians equals one complete revolution.

The distance traveled along a circular path.

The total distance around the outside of a circle (2πr).

The angle through which a radius of a circle rotates.

Radians are a unit for measuring angles, while degrees are another unit.

The acceleration that causes an object to move in a circular path.

A measure of a centrifuge's centripetal acceleration relative to Earth's gravitational acceleration.

A large centrifuge used to test astronaut tolerance to high accelerations.

ac = v²/r, where ac is centripetal acceleration, v is velocity, and r is radius of the circular path.

The centripetal acceleration of a car rounding a bend at 25 m/s on a 500m radius curve

The centripetal acceleration on a curve is a fraction of gravity (0.128g).

The centripetal acceleration increases with faster velocity and smaller radii.

A centrifuge capable of generating very high centripetal accelerations.

A force that opposes motion between two surfaces in contact, preventing movement until a certain threshold is reached.

A dimensionless number that represents the ratio of the force needed to overcome static friction to the normal force pressing the surfaces together.

The force exerted by a surface perpendicularly to an object in contact with it.

The force that keeps an object moving in a circular path. It always points towards the center of the circle.

A curved road that is tilted inward to help vehicles navigate the curve more safely.

The angle of a banked curve that allows a vehicle to negotiate the curve at a specific speed without relying on friction.

The maximum safe speed on a curve is independent of the car's mass. This means a heavier car can take the same curve at the same speed as a lighter car.

Banking a curve reduces the normal force acting on a vehicle, compared to a level curve. This is because a component of the normal force now contributes to the centripetal force.

The acceleration experienced by the Moon due to Earth's gravity, causing it to orbit.

The acceleration required to keep the Moon moving in a circular path around Earth.

The acceleration due to Earth's gravity at the Moon's distance is equal to the centripetal acceleration required for its orbit.

Newton recognized that the gravitational force causing the Moon's orbit is the same force that causes objects to fall on Earth.

The gravitational force between Earth and the Moon provides the centripetal force needed for the Moon's circular motion.

To calculate g at the Moon's distance, use the formula g = GM/r² where M is Earth's mass, r is the distance to the Moon, and G is the gravitational constant.

The formula for centripetal acceleration is ac = v²/r, where v is the orbital velocity of the Moon and r is its orbital radius.

Gravity is the force responsible for keeping planets, moons, and other celestial objects in orbit.

This law describes the gravitational force between any two objects with mass. The force is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centers of mass.

A fundamental constant used in Newton's Universal Law of Gravitation. Represents the strength of gravity and has a very small value, approximately 6.674 x 10^-11 N⋅m²/kg²

The point where the entire mass of an object is considered to be concentrated. This simplifies calculations for gravitational force.

A relationship where the force of gravity decreases as the square of the distance between two objects increases. Double the distance, the force becomes four times weaker.

The gravitational force is directly proportional to the product of the masses. This means that if you double the mass of one object, you double the gravitational force between them.

The force of attraction between any two objects with mass. It depends on the masses of the objects and the distance between them.

For every action (gravitational force), there is an equal and opposite reaction. This means that the force of gravity between two objects is the same on both objects but in opposite directions.

The gravitational force is very weak, especially on small scales, because the gravitational constant (G) is so small. This is why we don't feel the gravitational pull of everyday objects.

A condition where the force of gravity is significantly reduced, creating a near weightless environment. This occurs in space, where objects experience very little gravitational pull.

Astronauts experience muscle loss (atrophy) due to the lack of gravity in space. Without gravity, muscles don't need to work as hard to support the body, leading to weakening.

Astronauts experience a decrease in bone density due to microgravity. Bones weaken since they don't have to support weight against gravity's pull.

The heart adjusts to the lack of gravity in space. Blood flow changes, with less pressure on the lower body and more on the upper body. It's like the body redistributes blood.

Spending time in space weakens the human immune system, potentially making astronauts more susceptible to infections.

Some bacteria grow faster in space's microgravity than on Earth. This could pose health risks for astronauts.

Plants have evolved with gravity, but research shows they might be able to grow in space's microgravity. This could be key for long space missions.

Inorganic and protein crystals grown in space have much higher quality than those grown on Earth. This allows for better analysis of their structures.