Physics Unit 2A Test Review

linear speed

the rate at which an object moves along a straight path, typically measured in units such as meters per second. (m/s)

rotational speed

the rate at which an object rotates around an axis, usually measured in revolutions per minute. it describes how quickly an object spins or revolves compared to a fixed point.

centripetal force

the net force that acts on an object moving in a circular path, directed towards the center of the circle, enabling the object to maintain its circular motion.

centripetal acceleration

the acceleration experienced by an object moving in a circular path, directed towards the center of the circle, calculated as the change in velocity per unit time.

centrifugal effect

the apparent outward force experienced by an object moving in a circular path, due to its inertia, which seems to push it away from the center of rotation.

kepler’s first law

every planet orbits the sun in an elliptical path, with the sun at one of the ellipse's two foci.

kepler’s second law

a line segment joining a planet, and the sun sweeps out equal areas during equal intervals of time. implies that a planet moves faster when it is closer to the sun and slower when it is farther away.

kepler’s third law

the square of a planet's orbital period is directly proportional to the cube of the semi-major axis of its orbit.

law of universal gravitation

every mass attracts every other mass in the universe with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centers.

newton’s third law

for every action, there is an equal and opposite reaction. this means that forces always occur in pairs; when one object exerts a force on another, the second object exerts a force of equal magnitude and opposite direction on the first object.

impulse-momentum theorem

The change in momentum of an object is equal to the impulse applied to it. This principle connects the force applied over time to the resulting change in motion.

law of conservation of momentum

The total momentum of a closed system remains constant over time, provided no external forces act on it.

elastic collision

A type of collision in which both momentum and kinetic energy are conserved.

inelastic collision

A type of collision in which momentum is conserved but kinetic energy is not conserved, often resulting in deformation.

explosion

A type of interaction in which two or more bodies rapidly separate, resulting in a significant release of energy, typically with a rapid increase in momentum.

consider two planets in space. When the masses of both planets are doubled, what happens to the attractive force between them? use equations and proportional reasoning to model your answers.

1. Fg = G(m1)(m2)/r² (m=mass & r=distance)

2. Then plug in numbers according to problem and solve to find how attractive force changes according