Kinematics Flashcards
What is distance?
Measure of how far an object travels
Distance is a scalar quantity.
What is the SI unit of distance?
m
What is displacement?
Measure of how far something is from its starting position; the change in position is the shortest path between two points
Displacement is a vector quantity.
What is the SI unit of displacement?
m
What is speed?
The distance travelled every second; rate of change of distance
Speed is a scalar quantity.
What is the formula for average speed?
Average speed = total distance / time taken
What is the speed if an object travels 20 m in 1 second?
20 m/s
What is velocity?
Similar to speed but also describes the direction; rate of change of displacement
Velocity is a vector quantity.
What is the SI unit of velocity?
m/s
Can velocity be negative?
Yes
What is relative velocity?
V = V + Vr
Where V0 is the velocity of the observer and v is the velocity of the object.
What is acceleration?
Rate of change of velocity; describes how much an object’s velocity changes every second
Acceleration is a vector quantity.
What is the SI unit of acceleration?
m/s²
What is the formula for average acceleration?
Average acceleration = change in velocity / time taken
How is change in velocity calculated?
Change in velocity = final velocity - initial velocity
What is uniform acceleration?
Rate of change of velocity remains constant over time
What is the acceleration due to gravity?
g = 9.81 m/s²
What is non-uniform acceleration?
Acceleration of an object varies over time
What is negative acceleration?
Slowing down or accelerating in the negative direction
What is the definition of instantaneous value in physics?
Value of speed, velocity, or acceleration of an object at any given point in time.
What are the kinematic equations used for?
To describe any object moving with constant/uniform acceleration.
List the four kinematic equations.
- v = u + at
- s = ut + (1/2)at²
- v² = u² + 2as
- s = vt - (1/2)at²
In the equation v = u + at, what do the variables represent?
- v - final velocity
- u - initial velocity
- a - acceleration
- t - time interval
True or False: An object falling in a gravitational field without air resistance has an acceleration of g = 9.81 m/s².
True
Fill in the blank: If the initial velocity is not mentioned, it can be assumed to be _______.
0
What is the acceleration due to gravity typically denoted as?
g = 9.81 m/s²
What must the train’s speed be at marker 2 according to the scenario?
No more than 10 m/s
What is the initial speed of the train as it approaches marker 1?
50 m/s
What is the time interval required to pass from marker 1 to marker 2?
20 seconds
What equation links initial speed (u), final speed (v), time (t), and distance (s)?
s = ut + (1/2)at²
How far should marker 1 be placed from marker 2 if the train must decelerate uniformly?
600 meters
In the worked example, what is the calculated distance (s) when plugging in the variables?
600 m
What does ‘starts from rest’ imply about the initial velocity?
Initial velocity (u) is 0.
What happens to the sign of acceleration when an object is traveling upwards?
Acceleration must be treated as negative.
What is the significance of ‘constant acceleration in a straight line’?
Indicates that kinematic equations can be applied.
What does the slope/gradient represent in a displacement-time graph?
Velocity
A zero slope indicates rest
In a displacement-time graph, what does the y-intercept represent?
Initial displacement
What does a curved line in a displacement-time graph indicate?
Acceleration
What does the slope/gradient represent in a velocity-time graph?
Acceleration
In a velocity-time graph, what does the y-intercept represent?
Initial velocity
What does a straight, diagonal line in a velocity-time graph indicate?
Uniform acceleration
What does the area under the curve in a velocity-time graph represent?
Change in displacement
What does the slope represent in an acceleration-time graph?
Meaningless
In an acceleration-time graph, what does the y-intercept represent?
Initial acceleration
What does the area under the graph in an acceleration-time graph represent?
Change in velocity
Fill in the blank: The displacement-time graph for constant velocity shows a _______.
Straight line
Fill in the blank: The velocity-time graph for increasing velocity shows a _______.
Curved line
What is the direction of acceleration due to gravity on a bouncing ball?
Always downward
True or False: The assumption of no other forces on a bouncing ball means it reaches the same height every time.
True
At Point A of a bouncing ball’s motion, what is the velocity?
Low velocity (changes from positive to negative)
At Point B of a bouncing ball’s motion, what happens to the velocity?
Changes from negative to positive
True or False: The speed of the bouncing ball remains the same at minimum displacement.
True
What does positive velocity indicate in terms of direction?
Positive direction
What does negative velocity indicate in terms of direction?
Negative direction
What is the relationship between acceleration and velocity during the motion of a bouncing ball?
Acceleration is constant and vertically downward
What is projectile motion?
Particle moving freely under gravity in a two-dimensional plane
What assumptions are made in projectile motion?
- Resistance from air or liquid is negligible
- Acceleration due to gravity (g) is constant
What does ‘time of flight’ refer to?
How long the projectile is in the air
What is the maximum height in projectile motion?
Velocity = 0; occurs halfway through the time of flight
Define ‘range’ in the context of projectile motion.
Horizontal distance traveled by the projectile
Are the horizontal and vertical components of projectile motion independent?
Yes, they need to be evaluated separately using kinematic equations
What is the horizontal displacement at the end of projectile motion?
Maximum range
What happens to horizontal velocity (Vh) during projectile motion?
Vh is always constant
What is the vertical velocity (Vv) at maximum height?
Vv = 0
What is the acceleration in horizontal motion?
0
What is the constant vertical acceleration due to gravity?
Approximately 9.81 m/s²
In projectile motion, what is the resultant vertical velocity equation?
Vv = initial vertical velocity + (acceleration * time)
What is the initial vertical velocity (Uv) in a projectile launched at an angle?
Uv = Sin(angle) * initial speed
What is the initial horizontal velocity (Uh) in a projectile launched at an angle?
Uh = Cos(angle) * initial speed
Calculate the initial vertical velocity if the angle is 25° and initial speed is 30 m/s.
Uv = Sin(25°) * 30 = 12.68 m/s
Calculate the initial horizontal velocity if the angle is 25° and initial speed is 30 m/s.
Uh = Cos(25°) * 30 = 27.19 m/s
What is the formula for calculating the distance D in projectile motion?
D = Uh * time of flight
True or False: The vertical acceleration is positive when moving away from the Earth.
True
Fill in the blank: The stone hits the ground with a vertical velocity of ______.
33.8 m/s
What is the total distance D from the cliff base if Uh = 27.19 m/s and time of flight is 2.15 s?
D = 58.46 m
