ODU (part 1) Flashcards
What is a scalar?
A scalar is a quantity that has size (magnitude) only
What is a vector?
A vector is a quanity that has size (magnitude) and direction
Name 6 examples of scalars
Distance
Speed
Energy
Temperatire
Time
Volume
Name 5 vectors
Velocity
Displacement
Weight
Force
Define distance
Distance is a scalar. It is the total length of the path an object has travelled.
Define displacement.
Distance is a vector. It is a measure of how farn an object has moved directly from its start point to its finish point in a straight line.
What happens if an object changes its direction during a journey
its average speed and average velocity for the journey will be different.
Formula for speed
V= d/t
V= speed measured in metres per second (ms^-1)
d = distance measured in metres (m)
t = time measured in seconds (s)
Formula for velocity
V = s/t
V = velocity measured in metres per second (ms^-1)
s = displacement measured in metres (m)
t = time measured in seconds (s)
Define acceleration
acceleration (a) is the change in velocity per unit time
What is acceleration measured in
metres per second per second (ms^-2)
Describe an experiment to measure the acceleration of an object down a slope.
Use a cart with card on it, place it let it roll down a slope and use a light gate connected to a computer to find out its final speed and time taken to pass the light gate. substitue these values into the acceleration formula.
What are the 4 equations of motion
V = u + at
S = ut + 1/2at^2
V^2 = u^2 + 2as
S = 1/2(u+v)t
Where:
S = displacement measured in metres (m)
u = initial velocity measured in metres per second (ms^-1)
v = Final velocity measured in metres per second (ms^-1)
a = acceleration measured in metres per second per second (ms^-2)
t = time measured in seconds (s)
How to find displacement and acceleration in a velocity time graph
Find the area under the graph to find the displacement and gradient of the line to find the acceleration.
What are the conditions for equations of motion to be used
The motion is a straight line
The acceleration is constant
What is the acceleration due to gravity (Vertical motion)
-9.8 ms^-2 (downwards)
The final velocity of an object falling 10m would be (+/-)
negative
Tne initial velocity of an object being thrown upwards 10m would be (+/-)
positive
How do you find acceleration in a speed time graph
gradient of the graph.
How do you find distance travlled in a speed time graph
Area under the graph
How do you find displacement in a velocity time graph
area under the graph
How do you find the velocity in a displacement time graph
gradient
how do you find the acceleration in a velocity time graph
gradient
How do you find change in velocity in an acceleration time graph
area under the graph.