9th Grade Physics Motion Revision Flashcards

Comprehensive practice flashcards for 9th-grade physics revision on scalar and vector quantities, distance, displacement, speed, acceleration, deceleration, and motion graphs.

What grade level is specified for this physics test revision?

9th grade.

Which primary subject topics are listed for revision in the physics notes?

Scalar and vector quantities, distance and displacement, speed, distance and time, distance-time graphs and their interpretations, acceleration and deceleration, and vector-time graphs.

What is a scalar quantity?

A physical quantity that has magnitude only and no direction.

What is a vector quantity?

A physical quantity that has both magnitude and direction.

Is distance classified as a scalar or vector quantity?

Distance is a scalar quantity.

Is displacement classified as a scalar or vector quantity?

Displacement is a vector quantity.

How is distance defined in physics?

The total length of the path traveled by an object, regardless of direction.

How is displacement defined in physics?

The straight-line distance and direction from an object's initial position to its final position.

What is the standard SI unit for measuring distance and displacement?

Meters ($m$).

Can distance have a negative value?

No, distance is always positive or zero because it is a scalar quantity.

Is it possible for displacement to be zero when total distance traveled is greater than zero?

Yes, if an object returns to its exact starting point, its displacement is zero.

How is speed defined?

The rate at which an object covers distance over time.

What formula links speed, distance, and time?

$$\text{Speed} = \frac{\text{Distance}}{\text{Time}}$$

Is speed classified as a scalar or vector quantity?

Speed is a scalar quantity.

What is the SI unit for speed?

Meters per second ($m/s$).

On a distance-time graph, what variable is plotted on the vertical y-axis?

Distance.

On a distance-time graph, what variable is plotted on the horizontal x-axis?

Time.

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

Speed.

What does a horizontal flat line indicate on a distance-time graph?

The object is stationary (at rest).

What does a straight diagonal line with a constant positive slope represent on a distance-time graph?

Constant speed.

What does a steeper slope indicate on a distance-time graph?

A higher or faster speed.

What motion is indicated by a curve sloping upward on a distance-time graph?

Acceleration (increasing speed over time).

What is acceleration?

The rate of change of velocity (or speed) with respect to time.

What is the mathematical formula for calculating acceleration?

$a = \frac{v - u}{t}$ where $v$ is final velocity, $u$ is initial velocity, and $t$ is time.

What is the SI unit for acceleration?

Meters per second squared ($m/s^2$).

What is deceleration?

A decrease in speed or velocity over time, also known as negative acceleration.

How is deceleration represented numerically in acceleration calculations?

As a negative acceleration value.

On a vector-time (velocity-time) graph, what variable is plotted on the horizontal x-axis?

Time.

On a vector-time (velocity-time) graph, what variable is plotted on the vertical y-axis?

Velocity (or vector speed).

What physical quantity is represented by the slope (gradient) of a vector-time graph?

Acceleration.

What does a horizontal straight line above zero represent on a vector-time graph?

Constant velocity (zero acceleration).

What does a straight line sloping upward represent on a vector-time graph?

Constant (uniform) acceleration.

What does a straight line sloping downward represent on a vector-time graph?

Constant (uniform) deceleration.

What physical quantity does the area under a vector-time graph represent?

Distance or displacement.

What does a horizontal line along the x-axis (velocity = 0) represent on a vector-time graph?

The object is at rest (stationary).

How is time defined in motion calculations involving distance and speed?

The time duration or interval over which a movement occurs.

What is the standard SI unit for time?

Seconds ($s$).

How is distance calculated using speed and time?

$$\text{Distance} = \text{Speed} \times \text{Time}$$

How is time calculated using distance and speed?

$$\text{Time} = \frac{\text{Distance}}{\text{Speed}}$$

What is the main conceptual difference between speed and velocity?

Speed is a scalar quantity measuring magnitude only, whereas velocity is a vector quantity measuring magnitude with direction.

Name two scalar quantities covered in this revision unit.

Distance and speed.

Name two vector quantities covered or implied in this revision unit.

Displacement and velocity (vector-time).

Is acceleration classified as a scalar or a vector quantity?

Acceleration is a vector quantity.

If an object slows down from $10\,m/s$ to $2\,m/s$ in $4\,s$, what is its rate of deceleration?

$2\,m/s^2$ (calculated as $\frac{2 - 10}{4} = -2\,m/s^2$ acceleration).

How do you calculate the gradient on a distance-time graph?

$$\text{Gradient} = \frac{\text{Change in Distance}}{\text{Change in Time}}$$

How do you calculate the gradient on a vector-time graph?

$$\text{Gradient} = \frac{\text{Change in Velocity}}{\text{Change in Time}}$$

What does zero acceleration indicate about an object's motion?

The object is moving at a constant speed or remaining stationary.

What motion is shown by a curve on a distance-time graph that gets flatter over time?

Deceleration (decreasing speed).

Does distance or displacement depend on the actual path taken?

Distance depends on the path taken, whereas displacement depends only on the starting and ending points.

What overarching topic in 9th-grade physics do these revision concepts address?

Kinematics and motion, including scalar/vector quantities, speed, distance, time, acceleration, deceleration, and motion graphs.