Ap physics 1 exam

Displacement (Δx)

Net change in position, measured in meters (m). Formula: Δx = x(f) - x(i).

Velocity (v)

Speed and direction, measured in meters per second (m/s). Average velocity formula: v = Δx/t.

Acceleration (a)

Rate of change of velocity with respect to time, measured in meters per second squared (m/s^2). Average acceleration formula: a = Δv/t.

Speeding up vs. Slowing Down

Speeding up occurs when velocity and acceleration have the same sign; slowing down occurs when they have opposite signs.

Position vs. Time Graph

The slope represents average velocity; an object changes direction when the graph crosses the x-axis.

Velocity vs. Time Graph

The slope represents average acceleration; the area under the curve represents displacement.

Acceleration vs. Time Graph

The area under the curve represents change in velocity.

Scalars

Quantities with only a size/magnitude (e.g., speed, mass, length).

Vectors

Quantities with both a size and direction (e.g., displacement, velocity, force).

Projectile Motion

Horizontal and vertical components are independent; larger angles travel higher, smaller angles have greater horizontal velocities.

Force (F)

A push or pull measured in Newtons (N).

Newton's 1st Law

An object will maintain its velocity unless acted upon by another force.

Inertia

The property of an object that resists changes in motion, measured in mass.

Newton's 2nd Law

Net force equals mass times acceleration (F_net = m*a).

Newton's 3rd Law

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

Normal Force (Fn)

A contact force between two hard surfaces.

Weight

The force of gravity on an object, calculated as weight = mass * gravitational strength, measured in Newtons (N).

Mass

How much matter is in an object; mass is independent of the object's location, measured in kilograms (kg).

Static Friction (Fs)

The force that resists the motion of stationary objects; maximum static friction Fs (max) = Us x Fn.

Kinetic Friction (Fk)

The friction experienced when two objects slide against each other; Fk = Uk x Fn.

Hooke's Law

Describes the behavior of springs: Fs = kΔx, where k is the spring constant.

Momentum (p)

Defined as p = mv, measured in kg*m/s; momentum is conserved in collisions.

Impulse (J)

Impulse is the product of net force and time, also equal to change in momentum (J = F_net Δt = Δp).

Elastic Collisions

Collisions where both momentum and kinetic energy are conserved.

Inelastic Collisions

Collisions where momentum is conserved, but kinetic energy is not; completely inelastic collisions occur when objects stick together.

Translational Kinetic Energy (K)

Energy of an object in motion, measured in joules; K = 1/2 mv^2.

Gravitational Potential Energy (Ug)

Energy based on an object's position in a gravitational field, measured in joules; Ug = mgh.

Elastic Potential Energy (Ue)

Potential energy stored in a spring, measured in joules; Ue = 1/2 kx^2.

Work (W)

Work is the energy transfer that occurs when a force moves an object; W = FΔx cosϴ.

Power (P)

The rate at which work is done over time, measured in Watts (W); P = W/t.

Conservative Forces

Forces where the work done does not depend on the path taken, with mechanical energy conserved.

Nonconservative Forces

Forces where the work done does depend on the path taken, with mechanical energy not conserved.

Centripetal Acceleration

Acceleration directed towards the center of a circular path; Ac = v^2/r.

Conditions for Circular Motion

1. Net force must point toward center of circle. 2. Velocity must point tangent to circle.

Period (T)

The time taken to complete one full cycle or revolution; T = 2πr/v.

Frequency (f)

The number of cycles per second, measured in Hertz (Hz); f = 1/T.

Centripetal Force

The net force that acts on an object moving in a circular path, directed toward the center.

Fictitious Force

An apparent force that arises in a non-inertial frame of reference.

Newton's Universal Law of Gravitation

Fg = Gm1m2/r^2, where G is the universal gravitation constant.

Gravitational Fields

Fields created around objects with mass that exert a gravitational force on other masses.

Gravitational Field Strength

Varies with location; g = Gm2/r^2.

Gravitational Potential Energy in Outer Space

Ug = -Gm1m2/r, where r is the distance between masses; zero potential defined at infinity.

Orbiting

An object orbits when it has an initial velocity tangent to the Earth and gravity provides centripetal acceleration.

Circular vs. Elliptical Orbits

Circular: constant radius, constant Ug and K. Elliptical: changing radius affecting Ug and K.

Restoring Force

A force that acts to bring a system back to equilibrium; restoring force = kΔx.

Simple Harmonic Motion

A type of motion characterized by a restoring force; the period of SHM is T = 2π√(m/k) for springs.

Angular Frequency (w)

Measured in radians per second (rads/s); w = 2πf = 2π/T.

Amplitude (A)

The maximum displacement from the equilibrium position.

Displacement in SHM

Displacement is zero at equilibrium; maximum at extremes.

Velocity in SHM

First derivative of displacement; maximum velocity occurs at equilibrium.

Acceleration in SHM

Second derivative of displacement; maximum acceleration occurs at extreme positions.

Transverse Waves

Waves where particles vibrate perpendicular to the direction of wave travel.

Longitudinal Waves

Waves where particles vibrate parallel to the direction of wave travel.

Wavespeed

Depends on the properties of the medium; v = λf.

Superposition

When two waves interfere, resulting in either constructive (amplitude adds) or destructive (amplitude subtracts) interference.

Beats

Variations in sound intensity due to the interference of sound waves with slightly different frequencies.

Standing Waves

Formed by the continuous interference of two waves of equal amplitude and frequency.

Doppler Effect

Change in frequency due to the motion of source or observer; moving towards increases frequency.

Resonance

Occurs when an object oscillates at its natural frequency.

Rotational Position

Defined by angle θ, measured in radians.

Angular Velocity (w)

Change in angle per unit time; measured in radians per second (rads/s) or rpm.

Angular Acceleration (α)

Change in angular velocity over time, measured in radians per second squared (rads/s²).

Angular Kinematics

Describes the rotational motion; Δθ = 1/2 αt² + ω₀t + θ₀.

Torque (T)

Depends on force applied, distance from pivot, and angle; T = Fr sin θ.

Rotational Inertia (I)

The resistance to change in rotational motion; I = mr² for point mass.

Angular Momentum (L)

L = Iω; conserved in absence of net external torque.

Rotational Kinetic Energy (Krot)

Krot = 1/2 Iω².

Coulomb's Law

F = k|q1||q2|/r²; describes the electrostatic force between charged objects.

Conductors vs. Insulators

Conductors allow charge to flow freely; insulators restrict flow.

Voltage (V)

Electric potential energy per coulomb, measured in volts (V).

Current (I)

Rate of flow of charge, measured in amperes (A); flows in the direction positive charges would move.

Resistance (R)

Measure of the difficulty for electrons to move through a material, measured in Ohms (Ω).

Ohm's Law

V = IR; the resistance is constant in an ohmic device.

Parallel Circuit

Circuit with multiple paths; resistors share total current.

Series Circuit

Circuit with one path; current splits across resistors.

Power in a Circuit (P)

Rate of change in electrical energy; P = IΔV.

Energy Efficiency

Ratio of useful output energy to total input energy.

Light bulbs

Brightness depends on power; bulbs with less wattage shine brighter in series.