Quantities, Units, Measurement, & Math Flashcards
What is a quantity?
A property of an object or phenomenon that can be measured.
What are the 6 (total 7) SI base quantities/units that you need to know?
length, mass, time, electric current, temperature, amount of a substance, (light intensity)
What is the unit and symbol for distance?
- unit: meter(m)
- symbol in an equation: d
What is the SI unit for Length?
answer with as many connections as possible
Created by Colletti
m, meters
Created by Colletti
What is the difference between a unit and a symbol
A unit comes after a number (e.g. 12eggs, 1doz, 5m/s), while a symbol is a variable seen in an equation (e.g. Δv as seen in a = Δv/Δt)
What is the meaning of the “m” in 12m?
answer with as many connecting concepts as possible
Created by Colletti
- meters
- the SI unit for Length(l), Distance(d), Displacement (Δx), Radius(r)
Created by Colletti
What is the unit and symbol for mass?
- unit: kilogram(kg)
- symbol in an equation: m
Δx
answer with as many connecting concepts as possible
Created by Colletti
- displacement, change in position
- symbol in an equation
- xf - xi
- measured in meters
Created by Colletti
What is the unit and symbol for time?
- unit: second(s)
- symbol in an equation: t or ∆t
What does this symbol mean?
∆
- delta
- change in
- final value - initial value
What do we use to measure quantities other than the 7 base quantities?
Derived units (e.g. m/s, m/s2, N)
How do we work out derived units?
From the base units and the equations which relate the derived quantities to the base quantities.
What is a scalar quantity?
A quantity with magnitude but no direction. (e.g. time, mass, energy, speed, distance)
What is a vector quantity?
A quantity with magnitude and direction. (e.g. velocity, acceleration, force, displacement)
How do you calculate vectors in a straight line?
Add or subtract (depending on direction)
How do you calculate perpendicular vectors?
Use Pythagoras theorem.
Solve for xi
∆x = xf - xi
Created by Colletti
xi = xf - ∆x
Solve for xf
∆x = xf - xi
Created by Colletti
∆x + xi = xf
Solve for Δt
a = Δv/Δt
Created by Colletti
Δt = Δv/a
Solve for vi
vf2 = vi2 + 2aΔx
Created by Colletti
vi = √(vf2 - 2aΔx )
Solve for vf
vf2 = vi2 + 2aΔx
Created by Colletti
vf = √( vi2 + 2aΔx)
Solve for Δx
vf2 = vi2 + 2aΔx
Created by Colletti
Δx = (vf2 - vi2) / 2a
Solve for Δt
vf = vi + aΔt
Created by Colletti
Δt = (vf - vi) / a
Solve for μ
Ff = μFN
Created by Colletti
μ = Ff / FN
Solve for m
Fg = mg
Created by Colletti
m = Fg/g
True or False
“Fg” means F * g
Created by Colletti
False
In Fg, the g is a subscript, which serves as a description
How many meters is 5cm?
Created by Colletti
.05m
5cm*(1m/100cm) = .05m