Foundations of physics Flashcards
What is a physical quantity?
a property of an object or of a phenomenon that can be measured
What are the S.I. units of mass, length, and time?
kilogram (kg), metre (m), second (s)
What base quantities do the S.I. units A, K, and mol represent?
current, temperature, amount of substance
List the prefixes, their symbols and their multiplication factors from pico to tera (in order of increasing magnitude)
pico (p) 10–12, nano (n) 10–9, micro (μ) 10–6, milli (m) 10–3, centi (c) 10–2, deci (d) 10–1, kilo (k) 103, mega (M) 106, giga (G) 109, tera (T) 1012
What is a scalar quantity?
a quantity that has magnitude (size) but no direction
What is a vector quantity?
a quantity that has magnitude (size) and direction
What are the equations to resolve a force, F, into two perpendicular components, Fx and Fy?
x = FF cosθ y = FF sinθ
What is the difference between distance and displacement?
distance is a scalar quantity
displacement is a vector quantity
What does the Greek capital letter Δ (delta) mean?
‘change in’
What is instantaneous speed?
the speed of an object over a very short period of time
What does the gradient of a displacement–time graph tell you?
Velocity
How can you calculate acceleration and displacement from a velocity–time graph?
acceleration is the gradient
displacement is the area under the graph
What do the letters suvat stand for in the equations of motion?
s = displacement, u = initial velocity, v = final velocity, a = acceleration, t = time taken
Define stopping distance
the total distance travelled from when the driver first sees a reason to stop, to when the vehicle stops
Define thinking distance
the distance travelled between the moment when you first see a reason to stop to the moment when you use the brake
