UNIT 1 - Basic Physics Flashcards
Define scalar quantity
Scalar quantity only has magnitude
Define vector quantity
Vector quantity has both magnitude and direction
Name 8 scalar quantities
Distance
Speed
Mass
Energy
Volume
Area
Pressure
Density
Name 6 vector quantities
Displacement
Velocity
Force
Acceleration
Momentum
Electric current
How do u resolve vectors?
Trigonometry aka soh cah toa
Whichever sides of triangle u got u use to do sohcahtoa, so if u got adjacent and opposite u do toa, tan
How to resolve vectors into components
Horizontal is zcos(angle)
Verticle is zsin(angle)
Its just reversing resolving vectors ig
Equation for weight, w?
W=mg
Weight = Mass x gravity
(Gravity on earth = 9.81N)
What is equation for density
P = m/v
density = mass/volume
Define density
Measurement of how tightly a material is packed together, defined as the mass per unit volume. P= m/v
Unit for density
Kgm⁻³ or kg/m³
or for smaller units gcm⁻³
Define centre of gravity
The single point within a body at which the entire weight of the body may be considered to act
Define centre of mass
Point where the total mass of an object can be treated as a single point
What is the condition for the two positions of CoG and CoM to coincide?
CoG based on weight, CoM based on mass. So when the gravitational field across an object is uniform, the two are identical.
(Uniform meaning the same across the object i think)
At what point will an object tip over?
When the centre of GRAVITY passes the pivot
Define moment of force (about a point..?)
The moment of a force about a point is defined as the force x the perpendicular distance from the point to the line of action of the force
i.e (moment = force x distance)