Scalars and Vectors Flashcards
What 2 main sections can physical quantities in physics be divided into?
Scalars and vectors.
What to all scale quantities have?
Magnitude
Unit
What do all vector quantities have?
Magnitude
Unit
Direction
What are examples of scalar quantities and their units?
Time - s
Mass - kg
Temperature - k or oC
Distance - m
Speed - m/s
Charge - C
Energy - J
Power - W
What are examples of vector quantities and their units?
Displacement - m
Velocity - m/s
Acceleration - m/s2
Force - N
Momentum - kg m/s
Electric current - A
What is the scalar equation for speed?
Speed = distance / time
s = d / t
What are the scalar equations for average speed.
Av speed = distance / time OR Sav = d / t
Av speed = initial speed + final speed / 2 OR Sav = (u + v) / 2
What is the scalar equation for rate of change of speed?
Rate of change of speed = final speed - initial speed / time
Delta s = (v - u) / t
What is delta shown by?
A triangle
What does delta mean?
Change in
What are the vector equations for average velocity?
Av velocity = displacement / time OR v = s / t
Av velocity = initial velocity + final velocity / 2 OR v = (u + v) / 2
What is the vector equation for acceleration?
Acceleration = final velocity - initial velocity / time
a = delta v / t
What does delta v stand for?
Delta v = v - u
In a distance - time graph, what does it mean when the gradient is constant?
Speed is constant
In a distance - time graph, what does it mean when the gradient is zero?
Speed = 0
At rest
Which part of a distance - time graph is the journey fastest?
Where gradient is steepest.
How can speed be calculated in a distance - time graph?
Gradient = rise / run = d / t = s
In a speed - time graph, what does it mean when the gradient is constant?
Rate of change of speed is constant.
In a speed - time graph, what does it mean when the gradient is zero?
Rate of change of speed = 0
Moving with constant speed.
Over which part of a speed - time graph is the rate of change of speed largest?
At steepest gradient.
How can rate of change of speed be calculated in a speed - time graph?
Gradient = rise / run = s / t = delta s
How can the distance traveled be calculated in a speed - time graph?
Area under graph = distance traveled
d = A1 + A2
In a displacement - time graph, what does it mean when the gradient is constant?
Constant velocity.
In a displacement - time graph, what does it mean when the gradient is zero?
Velocity = 0
At rest.
Over which part of a displacement - time graph is the velocity largest?
At steepest gradient.
How can velocity be calculated in a displacement - time graph?
Gradient = rise / run = s / t = v
In a velocity - time graph, what does it mean when the gradient is constant?
Constant acceleration.
In a velocity - time graph, what does it mean when the gradient is zero?
Acceleration = 0
Constant acceleration.
Over which part of a velocity - time graph is the acceleration largest?
At steepest gradient.
How can acceleration be calculated in a velocity - time graph?
Gradient = rise / run = delta v / t = a
What is deceleration/ retardation?
When objects velocity is decreasing, then it is said to be decelerating.
Also known as retardation.
