02 motion Flashcards
What is the definition of rate?
Per unit time
What is the definition of speed?
Distance travelled per unit time
What is speed measured in?
m s‐¹
Is speed a vector or scalar quantity?
Scalar
What is the definition of a scalar quantity?
Magnitude but not direction
What is a definition of a vector quantity?
Magnitude and direction
What is the definition of displacement?
The distance moved in a straight line from a starting point
In displacement, if the starting point is the same as the finishing point, what is the final displacement?
0m
What is the definition of velocity?
The change in displacement per unit time
What is the S.I. unit for velocity?
m s‐¹
Is displacement a vector or scalar quantity?
Vector
In a results table how do you write a unit?
Title /unit
What is the precision of a ruler?
±1mm as it is measured in mm
What is the definition of precision?
The smallest non-zero reading that can be measured.
What happens to the velocity as the mass falls on the ticker time practical?
It’s accelerating. The velocity increases.
What are any sources of error in the time ticker experiment?
Air resistance, friction between tape and plastic loops.
How do you calculate the range?
Largest number — smallest number
How do you calculate the uncertainty?
Range/2
What is the smallest possible range? (Even if the range should =0)
0.01 (in a 2 d.p question) IT CANNOT EQUAL ZERO!
What is the smallest uncertainty? (Even if it should equal 0)
0.01 (in a 2 d.p question) IT CANNOT EQUAL ZERO!
How do you find the percentage uncertainty?
((Uncertainty) / (average value)) x100
How can the final (eg) speed be found from the average (eg) speed?
Double the average (eg)speed.
What are some sources of error when measuring the speed of a trolley using a light gate?
Air resistance, friction in between the wheels and the ramp, angle the trolley moves, the trolley is accelerating so the calculated speed wont be accurate.
What do you do if your uncertainty or range is to more d.p than in the question/the measurement?
Make it 0.01 (in at 2d.p question)
What is acceleration?
The rate of change in velocity.
What is acceleration measured in?
m s‐ ²
Is acceleration a vector or scalar quantity?
Vector
What is the formula for acceleration?
a= v/t
When does uniform acceleration occur?
When the velocity changes by the same amount each second.
When does non-uniform acceleration occur?
When the velocity change each second varies.
In velocity time graphs, what is the gradient of the line equal to?
The acceleration
In velocity time graphs, what is the area under the line equal to?
Change in displacement.
What is the equation for displacement?
Velocity x time
What are ‘suvat’ equations?
Equations of motion
What can ‘suvat’ equations be used to calculate?
S=displacement
U=initial velocity
V=final velocity
A=acceleration
T=time taken
What is freefall?
When there is gravity acting on an object and nothing else.
What is the definition of freefall?
The motion of an object undergoing an acceleration of ‘g’.
In which direction does ‘g’ act?
Vertically downwards
What is the magnitude of ‘g’?
Usually 9.81 m s‐², though it varies slightly at different points on the earth’s surface.
What force acts on an object in freefall?
Weight
In which situation can objects with an initial velocity in any direction and undergo freefall?
As long as the force providing the initial velocity is no longer acting.
What happens when there is an absolute systematic error?
Non-zero y-intercept.
Why and how can you use ‘suvat’ equations to find ‘g’ during freefall?
You substitute ‘g’ for ‘a’ (acceleration) as ‘g’ is a constant acceleration.
Describe the motion of this graph
The object is stationary with a positive displacement.
Describe the motion of this object
The object is moving at a constant positive velocity away from the origin.
Describe the motion of this object
The object is accelerating with a positive acceleration away from the origin.
