Forces And Motion Flashcards
What is speed defined as?
The distance travelled per unit time
Speed is a scalar quantity.
What does it mean if the speed of something is changing?
It is accelerating or decelerating
Acceleration is a change in speed over time.
What is the formula for average speed?
average speed = total distance / total time
This formula calculates the mean speed over a specific distance.
What is velocity?
The speed in a given direction
Velocity is a vector quantity.
What is acceleration?
The change in velocity per unit time
Acceleration can be positive (speeding up) or negative (slowing down).
What is the formula for acceleration?
acceleration = change in velocity / time
It can also be expressed as a = (final speed - initial speed) / time.
What is the equation relating final speed, initial speed, acceleration, and distance?
(final speed)² = (initial speed)² + (2 × acceleration × distance)
This equation is useful in kinematic calculations.
In which units is distance measured?
Metres (m)
Distance is a scalar quantity.
In which units is time measured?
Seconds (s)
Time is a scalar quantity.
In which units is speed and velocity measured?
Metres per second (m/s)
Both are scalar and vector quantities, respectively.
In which units is acceleration measured?
Metres per second squared (m/s²)
Acceleration indicates how quickly velocity changes.
What does a gradient represent in a displacement-time graph?
Velocity
The steepness of the gradient indicates the speed of the object.
What does a negative gradient in a displacement-time graph indicate?
Returning back to the starting point
This indicates a change in direction.
What does a horizontal line in a displacement-time graph mean?
It is stationary
No displacement means no movement.
What does a curved line in a displacement-time graph indicate?
The velocity is changing (accelerating/decelerating)
The curvature reflects a non-constant speed.
What does the gradient represent in a velocity-time graph?
Acceleration
The steeper the gradient, the greater the acceleration.
What does a negative gradient in a velocity-time graph indicate?
Deceleration
This shows a reduction in speed over time.
What does a horizontal line in a velocity-time graph mean?
Constant speed
The object travels at the same speed throughout the time interval.
What does the area under the line in a velocity-time graph represent?
The distance travelled
This is useful for calculating total distance from speed over time.
What does a curved line in a velocity-time graph indicate?
The acceleration is changing
The curvature reflects a non-constant acceleration.
Fill in the blank: If the speed is zero, it is _______.
at rest
This indicates no movement.
What is the difference between a vector and a scalar?
A vector has magnitude and direction; a scalar has just a magnitude.