General Physics 1: Kinematics, Motion, and Free Fall Flashcards

Flashcards covering concepts, definitions, kinematic equations, speed, velocity, acceleration, uniformly accelerated motion, and free fall based on the General Physics 1 lecture.

What is kinematics and from which Greek word is it derived?

Kinematics is the study of the mathematical description of motion. The term is derived from the Greek word kinema, meaning movement.

What is the difference between distance and displacement?

Distance is a scalar quantity that represents the total path taken or traveled by an object. Displacement is a vector quantity that measures an object's change in position relative to a reference point from the initial position to the final position.

What is instantaneous speed?

Instantaneous speed is the speed of an object for a specific time or for an instant in time.

How can a moving object have a zero average velocity but a non-zero instantaneous velocity?

A moving object will have zero average velocity if it returns to its original position because its net displacement is zero, even though its instantaneous velocity throughout the motion was non-zero.

What is the main distinction between speed and velocity?

Speed is a scalar quantity measuring distance over time regardless of direction, while velocity is a vector quantity measuring displacement over time, considering initial and final positions along with direction.

If a bus covers $3.5\,\text{km}$ ($3,500\,\text{m}$) in $4\,\text{minutes}$ ($240\,\text{s}$), what is its average speed?

The average speed is $15\,\text{m/s}$.

How far can Emily travel in $2\,\text{hours } 30\,\text{minutes}$ if she drives at a constant speed of $80\,\text{km/h}$?

She can travel a distance of $200\,\text{km}$.

What is the average speed of a car that travels $500\,\text{meters}$ in $10\,\text{seconds}$?

The average speed is $50\,\text{m/s}$.

What is Lebron's velocity if he bikes $800\,\text{meters}$ to the left in $25\,\text{seconds}$?

His velocity is $32\,\text{m/s}\text{ to the left}$.

How is acceleration defined and how is its direction determined?

Acceleration is the rate of change in velocity ($a = \frac{\Delta v}{\Delta t}$). Its direction follows the direction of the vector with the higher magnitude.

What does negative acceleration indicate?

Negative acceleration indicates that speed decreases over time, which is referred to as deceleration.

If a car moving initially at $2.0\,\text{m/s}$ reaches $16.0\,\text{m/s}$ after $5.0\,\text{s}$, what is its acceleration?

The acceleration of the car is $2.8\,\text{m/s}^2$.

Sarah drives a car that accelerates from an initial velocity of $10\,\text{m/s}$ to $30\,\text{m/s}$ in $4\,\text{seconds}$. What are the acceleration and average velocity?

The acceleration is $5\,\text{m/s}^2$ and the average velocity is $20\,\text{m/s}$.

What is Uniformly Accelerated Motion (UAM)?

Uniformly Accelerated Motion is the motion of an object where the acceleration is constant.

In Uniformly Accelerated Motion (UAM), which kinematic equation is used when displacement $d$ is the missing variable?

The equation used is $v_f = v_i + a \cdot t$.

In Uniformly Accelerated Motion (UAM), which kinematic equation is used when time $t$ is the missing variable?

The equation used is $v_f^2 = v_i^2 + 2 \cdot a \cdot d$.

A car covers $200.0\,\text{m}$ while increasing its velocity from $20.0\,\text{m/s}$ to $30.0\,\text{m/s}$. What is its acceleration?

The acceleration is $+1.25\,\text{m/s}^2$.

Starting from rest, a car accelerates at $+2.0\,\text{m/s}^2$. How far will it go after $6.0\,\text{s}$?

The car will go $36.0\,\text{m}$.

What is a free-falling object?

A free-falling object is an object that is falling under the sole influence of gravity.

When air resistance is neglected, what is the rate of acceleration for a freely falling body near Earth?

Its velocity increases by $9.8\,\text{m/s}$ after every second, which corresponds to an acceleration due to gravity of $9.8\,\text{m/s}^2$.

A stone dropped from a bridge splashes into the river below after $3.0\,\text{s}$. How high is the bridge above the river?

Using $g = 9.80\,\text{m/s}^2$, the bridge is $44.1\,\text{m}$ high.

What sign convention is used for vector quantities and gravitational acceleration when an object is thrown upward?

All vector quantities directed upward are considered positive, vector quantities directed downward are considered negative, and acceleration due to gravity is directed downward with the symbol $-g$.

What is the velocity of an object at its peak when projected upward?

At its peak or maximum height, the velocity of the object is $0\,\text{m/s}$.

What are the formulas for time to reach maximum height ($t$) and maximum height reached ($d$) for a vertical projectile?

The time to reach maximum height is $t = \frac{v_i}{g}$ and the maximum height reached is $d = \frac{v_i^2}{2g}$.

What is the formula for the total time of flight ($T$) of an object projected vertically upward that returns to its original position?

The formula for the total time of flight is $T = \frac{2v_i}{g}$.

A ball is thrown upward with an initial velocity of $40.0\,\text{m/s}$. What are the values for $t$, $d$, $T$, and return velocity $v_r$?

Using $g = 9.80\,\text{m/s}^2$: time to maximum height $t = 4.08\,\text{s}$, maximum height $d = 81.6\,\text{m}$, total time of flight $T = 8.16\,\text{s}$, and return velocity $v_r = -40.0\,\text{m/s}$.