Physics of Everyday Life: Rotational Motion and Kinematics (Chapter 1 & 2 Physics)

Flashcards generated from Chapter 1 and Chapter 2 of How Things Work: The Physics of Everyday Life (Louis A. Bloomfield).

Rotational Motion

Motion around a fixed point that prevents translation.

Angular Position

An object's orientation defined by an angle relative to a fixed reference line.

Angular Displacement

The angle through which an object rotates during a specific time interval.

Average Angular Speed ($\omega$)

The ratio of the angular displacement to the time interval, measured in $\text{rad/s}$.

Angular Velocity

A vector quantity combining an object's angular speed with its direction of rotation, determined using the right-hand rule.

Angular Acceleration ($\alpha$)

The ratio of the change in angular speed to the time required for that change, measured in $\text{rad/s}^2$.

Torque ($\tau$)

The combination of an applied force and its point of application that causes an object to rotate.

Lever Arm ($L$)

The perpendicular distance from the axis of rotation to the point where a force is applied.

Newton's Second Law of Rotational Motion

The law stating that torque equals rotational mass times angular acceleration ($\tau = I \times \beta$ or $\tau = I \times \nu$).

Torque Wrench

A wrench that applies a calibrated torque to a bolt to prevent over-tightening and breakage.

Translational Equilibrium

The state of an object when the net force acting on it is equal to zero ($\text{net force} = 0$).

Rotational Equilibrium

The state of an object when the net torque acting on it is equal to zero ($\text{net torque} = 0$).

Newton's Third Law of Rotational Motion

The principle stating that when object A exerts a torque on object B, object B exerts an equal but opposite torque on object A.

Center of Mass

The average position of all the mass that makes up an object.

Center of Gravity (CG)

The average position of weight distribution in an object, which determines its stability.

Rotational Mass (Moment of Inertia, $I$)

A measure of an object's resistance to rotational acceleration, depending on its mass and how far that mass is located from the axis of rotation.

Friction

A force acting between two contacting surfaces that always acts to oppose relative motion.

Static Friction

The resistive force between contacting surfaces that prevents them from sliding relative to each other up to a maximum value.

Kinetic Friction

The resistive force acting between two surfaces sliding past one another, which is typically smaller than maximum static friction.

Rotational Kinetic Energy

The energy an object possesses due to its circular motion, given by $K = \frac{1}{2} I \times \nu^2$.

Linear Momentum ($p$)

The product of an object's mass and its velocity ($p = m \times v$).

Conservation of Momentum

The principle stating that the total momentum of an isolated system before a collision is equal to the total momentum after the collision.

Elastic Collision

A collision in which two objects bounce off each other with no loss of kinetic energy.

Inelastic Collision

A collision in which objects bounce off each other with some loss of energy.

Completely Inelastic Collision

A collision in which two objects stick together after impact, resulting in the maximum possible loss of kinetic energy.

Impulse

The product of an applied force and the time interval over which it acts, resulting in a change in linear momentum.

Recoil

The backward movement acquired by a firing mechanism (such as a cannon) to conserve total linear momentum when launching a projectile.

Angular Momentum

A measure of the rotational motion of an object, calculated as rotational mass times angular velocity ($L = I \times \nu$).

Angular Impulse

The product of applied torque and the time interval over which it acts ($\text{angular impulse} = \tau \times \text{time}$).

SI Units (Système International)

The standardized system of units agreed upon internationally in 1960, also known as the mks system (meter, kilogram, second).

Scalar Quantity

A physical quantity that is completely specified by magnitude alone without direction.

Vector Quantity

A physical quantity that requires both magnitude and direction to be completely described.

Position

The location of an object described relative to a chosen origin or reference frame.

Distance

A scalar measure of the actual total path length followed between two points.

Displacement

A vector quantity representing the shortest distance and direction from an initial position to a final position.

Speed

A scalar quantity measuring how fast an object is moving, defined as $\text{speed} = \frac{\text{distance}}{\text{time}}$.

Velocity ($v$)

A vector quantity that specifies both the speed and direction of motion, given by $v = \frac{d}{t}$.

Acceleration ($a$)

The rate at which velocity changes over time, calculated as $a = \frac{v_f - v_i}{t_f - t_i}$.

Inertia

The natural resistance of any physical object to changes in its state of motion or velocity.

Newton's First Law of Motion

Galileo's principle stating that a body at rest tends to remain at rest, and a body in motion tends to remain in motion on a straight path unless acted upon by an external net force.

Newton's Second Law of Motion

The principle stating that an object's acceleration is directly proportional to the net force acting on it and inversely proportional to its mass ($a = \frac{F_{\text{net}}}{m}$).

Net Force

The vector sum of all individual forces acting simultaneously on an object.

Newton's Third Law of Motion

The law stating that whenever one object exerts a force on a second object, the second object exerts an equal and opposite force on the first.

Mass

The quantity of matter in an object and the quantitative measure of its inertia, measured in kilograms ($\text{kg}$).

Weight ($w$)

The force exerted on an object due to gravitational attraction, calculated as $w = m \times g$.

Acceleration Due to Gravity ($g$)

The constant downward acceleration experienced by freely falling objects near a planetary body, approximately $9.80665\text{\thinspace}m/s^2$ or $10\text{\thinspace}m/s^2$ on Earth.

Free Fall

The motion of an object falling under the influence of gravity alone, with negligible air resistance.

Projectile Motion

Two-dimensional curved motion experienced by an object launched into the air that moves under the sole influence of gravity.

Support Force (Normal Force)

The upward force exerted by a supporting surface on an object to balance its weight.

Work ($W$)

The product of the force applied to an object and the distance through which that force causes the object to move ($W = F \times d$), measured in Joules ($\text{J}$).