Motion Graphs and Kinematics

Flashcards testing core concepts of motion graphs, speed, velocity, acceleration calculations, and graph interpretation from lecture notes.

How is speed defined, and what is its equation?

Speed is distance travelled per unit time (or per second), given by the equation $v = s/t$, where $v$ is speed, $s$ is distance, and $t$ is time.

What is the formula for calculating average speed?

Average speed is calculated using the equation $\text{average speed} = \frac{\text{total distance}}{\text{total time}}$.

How is velocity defined in motion physics?

Velocity is defined as speed in a given (or stated) direction.

How is acceleration defined, and what equation represents it?

Acceleration is defined as the change in velocity per unit time, represented by the equation $a = \frac{\neq v}{\neq t}$.

What is the difference between acceleration and deceleration?

An object moving with increasing speed is accelerating, whereas an object moving with decreasing speed is decelerating.

What physical quantity does the gradient of a distance-time graph represent?

The gradient of a distance-time graph represents the speed of the object.

What physical quantities do the gradient and the area under a speed-time graph represent?

The gradient of a speed-time graph represents acceleration, while the area under a speed-time graph represents the distance travelled.

What line shape on a distance-time graph indicates that an object is stationary?

A horizontal line with a gradient of zero indicates that the object is stationary.

On this distance-time graph, which labeled line represents acceleration, constant speed, stationary, and deceleration?

Line a represents acceleration, line b represents constant speed, line c represents stationary, and line d represents deceleration.

In the provided distance-time graph, what motion is described in section B?

Section B represents a stationary object.

In the provided distance-time graph, what type of motion occurs in section G?

Section G represents constant speed in reverse (negative velocity).

Why does the velocity of a runner change along a circular or curved track even if their speed stays constant at $7\,m/s$?

Velocity includes direction, so even if speed remains constant at $7\,m/s$, velocity changes because the direction of motion changes continuously.

What is the acceleration of a horse accelerating from $5.0\,m/s$ to $10\,m/s$ in $2.0\,s$?

The acceleration is $2.5\,m/s^2$.

What is the acceleration of a high-speed train accelerating from $35\,m/s$ to $245\,m/s$ in $10\,s$?

The acceleration is $21\,m/s^2$.

What is the acceleration of a car accelerating from $0$ to $60\,m/s$ in $10\,s$?

The acceleration is $6\,m/s^2$.

What is the deceleration of a speedboat slowing from $95\,m/s$ to $60\,m/s$ in $5.0\,s$?

The deceleration is $7\,m/s^2$.

According to the speed-time graph, what is the acceleration from $0$ to $10\,s$?

The acceleration is $\frac{\Delta v}{\Delta t} = \frac{40 - 0}{10 - 0} = 4\,m/s^2$.

According to the speed-time graph, what is the distance travelled from $30$ to $50\,s$?

The distance travelled is the area of the triangle: $d = \frac{1}{2} \times \text{base} \times \text{height} = \frac{1}{2} \times 20 \times 60 = 600\,m$.

On the provided speed-time graph, what motion is occurring during section O-A?

Section O-A represents constant acceleration.

On the provided speed-time graph, what motion occurs in section U-V?

Section U-V represents accelerating motion.

On the labeled speed-time graph, which line corresponds to constant deceleration?

Line c (the blue line) represents constant deceleration.