Describing Motion Around Us - Practice Flashcards

These flashcards cover vocabulary related to describing motion, including linear motion, displacement, velocity, acceleration, and circular motion as presented in the lecture materials.

Linear motion

Motion of an object in a straight line.

Reference point

A fixed point used to describe the position of an object by specifying its distance and direction relative to this point.

Motion

A state reached if the position of an object with respect to a reference point changes with time.

Rest

A state reached if the position of an object with respect to a reference point does not change with time.

Origin 'O'

The reference point marked on a straight line used to represent the starting point or zero position.

Displacement

The net change in the position of an object between two given instants of time, requiring both direction and numerical value.

Magnitude

The numerical value (with units) of a physical quantity.

Scalars

Physical quantities that can be specified by just their numerical value.

Vectors

Physical quantities that require specifying both direction and magnitude.

SI unit of distance and displacement

The metre ($\text{m}$).

Average speed

The total distance travelled divided by the time interval during which the distance is covered.

Uniform motion

Motion in a straight line where an object travels equal distances in equal intervals of time.

Non-uniform motion

Motion in a straight line where an object travels unequal distances in equal intervals of time.

Aryabhatiya

A 5th century CE Indian treatise containing the concept that an object's speed is the distance travelled divided by time.

Ganitakaumudi

A 14th century CE comprehensive mathematical text that includes problems based on speed and time.

Average velocity

The change in position (displacement) divided by the time interval in which the change occurs.

Rate of change

The ratio of change in one quantity to the corresponding change in time.

Instantaneous velocity

The velocity of an object at a particular, infinitesimally small instant of time.

Average acceleration

The change in velocity divided by the time interval over which the change occurs.

SI unit of average acceleration

$\text{m/s}^2$ or $\text{m } s^{-2}$.

Acceleration due to gravity ($g$)

The constant vertical acceleration experienced by objects falling toward Earth, approximately equal to $9.8 \text{ m } s^{-2}$.

Slope (of a graph line)

The steepness of a line representing the rate of change of the quantity on the Y-axis with respect to the quantity on the X-axis.

Area enclosed by velocity-time graph and time axis

A geometric property equal to the displacement of the object during the given time interval.

Kinematic equations

A set of three formulas ($v = u + at$, $s = ut + \frac{1}{2}at^2$, and $v^2 = u^2 + 2as$) that describe motion with constant acceleration.

Motion in a plane

Motion in two dimensions, such as a ball's path after being kicked or a satellite's orbit.

Uniform circular motion

The motion of an object along a circular path at a constant (uniform) speed.

Tangent

A straight line that meets a circle at one and only one point, indicating the direction of velocity in uniform circular motion.