GEN PHY 1 2ND QUARTER

rigid body

is an extended object (not a point particle) with a definite shape. This means that the body’s particle stay in fixed positions relative to one another.

Torque (τ)

is the force that acts in any direction other than toward or away from the center of motion. It is also the rotational analog.

net external force

changes an object's linear momentum

net external torque

changes an object's angular momentum

not equal

The angular momentum of the objects is ______ to its linear momentum multiplied by the radius of its circular path.

Torque

is the rotational equivalent of force.

linear motion

force makes an object move forward or backward.

rotational motion

torque makes an object rotate around an axis, pivot, or fulcrum.

Torque

is the measure of the turning effect of a force applied at a distance from a point of rotation.

Newton’s Third Law of Motion

for every action, there is an equal and opposite reaction.

Gravity

fundamental force that attracts objects with mass toward each other

Johannes Kepler

discovered 3 laws of planetary motion

Kepler’s 1st Law

planets orbit the Sun in ellipses, with the Sun at one focus

Kepler’s 2nd Law

a line joining a planet and the Sun sweeps equal areas in equal times

Kepler’s 3rd Law

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

Centrifugal Force

apparent outward force in rotating systems

Force

changes an object’s linear momentum

Torque

changes an object’s angular momentum

Right-Hand Rule

We use the ______ to find the direction of torque.

vector quantity

Torque is a _______ because it has both magnitude and direction (axis of rotation).

radians per second squared (rad/s2)

The unit is ______because it measures how fast angular velocity changes.

2 : 5

A rolling sphere’s rotational : translational kinetic energy =

Mass

is the amount of matter

weight

is the force of gravity (mg) acting on mass.

Perihelion

Closest point:

Aphelion

Farthest point:

Escape Speed

It’s the minimum speed needed for an object to leave a planet’s gravity forever.

Massless objects

cannot exert gravitational force.

mechanical waves

Waves that need a medium to travel (like air or water) are called

Transverse Waves

Particles move up and down, perpendicular to the wave direction.

Longitudinal Waves

Particles move back and forth, parallel to the direction of the wave.

Equilibrium Line

The rest position of a medium when there’s no disturbance.

Crest

The highest point in a transverse wave.

Trough

The lowest point in a transverse wave.

Amplitude

The maximum height from the equilibrium line to a crest or trough — indicates wave energy.

Waves

A wiggle in space and time — can travel through matter or even vacuum (like EM waves).

Doppler Effect

The change in frequency or pitch when a sound source moves relative to you.

Oscillation

A back-and-forth periodic motion (like a pendulum swinging).

Electromagnetic Waves

Do not need a medium — can travel through space (example: light, radio waves).

Waves Transfer Energy

Waves carry energy, not matter. The medium moves only slightly while energy passes through.

Rarefaction

Region of low pressure or low density in a longitudinal wave.

Simple Harmonic Motion (SHM)

Occurs when acceleration is directly proportional and opposite to displacement (a = −ω2x).

Resonance

When an object is forced to vibrate at its natural frequency, it vibrates with greater amplitude.

Sinusoidal Waves

A _____ comes from the projection of uniform circular motion, also called the circle of reference.