AS mechanics Flashcards
how many kg in a tonne
1000 kg = 1 tonne
how many mg in a gram
1000 mg = 1g
how many nano metres in a metre
1 x 10^9 nano metres
what are the main units used in mechanics for:
- length
- time
- mass
- metres
- seconds
- kg
are the following quantities scalars or vectors :
- mass
- weight
- scalar
- vector, it is a force so it has a direction
what is acceleration measured in
metres per second squared
what is force measured in
newtons
how do you calculate force
force = mass x acceleration
what are derived units
a combination of S I units
is force a scalar or vector
- vector, it has a magnitude and direction
what is tension
- a pulling force that acts away from the objects
what is thrust
- a pushing force that acts towards objects
- also known as compression
can a string have the force of thrust acting on it
- no, a string can only every experience tension
- if pushed, a string will go slack
what is friction
- a resistive force that acts in the opposite direction to motion
- acts between two touching objects
- e.g. air resistance, water resistance
how do you calculate weight
weight = mass x gravity
what is the normal reaction force
- the force acting perpendicular to the line of contact between two objects
- ALWAY occurs between two objects
what is driving force
- force typically created by an engine that causes the vehicle to accelerate
what is braking force
- a resistive force caused by a vehicle, making is decelerate
- what is fluid resistance
- a resistive force depending on the viscosity of a fluid
e.g. swimming through honey instead of water
what does it mean when the sum of a particles vector forces are equal to 0
- the particle is in equilibrium
how do you find the magnitude of a vector
Pythagoras
how do you find the direction of a vector
trigonometry
