Topic 3 Kinematics Flashcards
What are scalar quantities.
They only have magnitude
What are vector quantities?
They both have magnitude and direction.
What is the formula for velocity?
Change in displacement/time
V = /\s / /\t
What is the formula of acceleration?
Change in velocity/time
a = /\v / /\t
What are the three types of graph that can represent motion?
Displacement-time graphs, velocity-time graphs and acceleration-time graphs
What does the y-intercept represent in a displacement-time graph?
It equals the initial displacement
What does a diagonal straight line represent on a displacement-time graph?
This represents constant velocity
What does a positive slope represent in a displacement-time graph?
It represents motion in the positive direction
What does a curved line represent in a displacement-time graph?
It represents acceleration
What does a straight line represent in a displacement-time graph?
A horizontal line represents a state of rest
What is the difference between a distance-time graph and a displacement-time graph?
A displacement-time graph can have a positive or negative value but a distance-time graph.
What does a slope represent in a velocity-time graph
Slope represents acceleration
What does the y-intercept represent in a velocity-time graph
The y-intercept equals the initial
What does a straight line represent in a velocity-time graph
It represents uniform acceleration
What does a positive slope represent in a velocity-time graph
An increase in velocity (acceleration) in the positive direction.
What does a curved line represent in a velocity-time graph
It represents the non-uniform acceleration.
What does a horizontal line (zero slope) represent in a velocity-time graph
It represents motion with constant velocity
What does a the area under the curve represent in a velocity-time graph
It equals the displacement or distance travelled
Difference between a velocity-time graph or speed-time graph
The velocity-time graph can have a positive or negative values on the displacement axis. However, a speed-time graph only has positive.
What does the y-intercept represent in an acceleration-time graph
It equals the initial acceleration
What does a horizontal line (zero slope) represent in an acceleration-time graph?
An object undergoing constant acceleration.
What does the area under the curve equal in an acceleration graph
It equals the change in velocity
What does the velocity equal in a displacement-time graph?
The gradient of a displacement-time graph
For a bouncing ball, when does the velocity change?
Since it changes direction at the highest and lowest point, the velocity changes.
What are the 4 us at equations?
V=u+at
S=ut+1/2at^2
S=(v+u)/2 x t
v^2 = u^2 +2as
What does start in rest mean in a question?
It means that u=0 and t=0 if both are not mentioned in the question
What does the acceleration of free fall mean?
The acceleration of free fall ,g, is defined as the acceleration of any object in response to the gravitational attraction between the Earth and the object.
What is the stopping distance of a car?
The distance it travels in the time it takes to stop in response to an emergency.
What is the equation of stopping distance?
Thinking distance + braking distance
The thinking distance is proportional to the s
Speed
Thinking distance definition
The distance travelled by the vehicle from when the driver sees a problem and the brakes are applied.
Thinking distance formula
Thinking distance = initial speed x reaction time
Factors that affect thinking distance
- The initial speed of the vehicle
- Intoxication
- Distractions (mobile phones)
- Tiredness
Braking distance defined as
The distance travelled by the vehicle after the driver has applied the brake
Work done formula with braking distance
Work done = braking force x braking distance
= 1/2 mv^2 kinetic energy equation
Factors that affect braking distance
- The initial speed of the vehicle
- Mass of the vehicle
- Poor road conditions
- Poor car conditions
What components do projectile motion have?
A horizontal and vertical component
Time of flight def
How long the projectile is in the air
Maximum height attained def
The height at which the projectile is momentarily at rest.
