Mechanics 1 Flashcards
Vectors and Scalars
Vectors have both magnitude and direction
Scalars have magnitude only
Displacement
Distance travelled in a particular direction
Speed
Distance/time
Velocity
Displacement/time
Acceleration
Final-initial velocity/time
Ticker tape timer formula
S/0.02 x number of spaces
g is negative when..
g is positive when..
Moving up
Moving down
Experiment to measure acceleration due to gravity graph
/
2s|_____. /
t^2
Newton’s 1st law
A body continues in a state of rest or uniform motion in a straight line unless a resultant external force acts on it
Friction
Benefits
Nuisances
Force that opposes the relative motion of 2 objects in contact
Allows car breaks to stop the car
Causes wearing in machines
Momentum
m x v
Inertia
Refusal of an object to change their state of motion
State Newton’s 2nd law and show how it leads to F=ma
The rate of change of the momentum of a body is proportional to the force that acts on it
Force proportional to rate of change of momentum
F proportional mv-mu/t
F proportional m(v-u/t)
F proportional ma
F=k x ma
F=ma
Show acceleration is proportional to force graph
N| /
|______. /
a
Newton’s 3rd law
To every action there is an equal and opposite reaction
Law of conservation of momentum
m1u1+m2u2=m1v1+m2v2 (in a closed system)
Or
When 2 or more bodies interact in a closed system the total momentum of bodies before interaction equals total momentum of bodies after interaction
Work
Force times displacement
Joules
1J=1N x 1m
Energy
Conservation of energy
Ability to do work
Energy cannot be created or destroyed but can be changed from one form to another
Kinetic energy
Potential energy
Energy an object has due to its motion
Energy an object has due to its position shape or size
Power
Rate at which work is done
Watt
1W=1J/1s
Renewable sources of energy
Non renewable sources of energy
Hydroelectricity, wind energy, solar energy, biomass
Oil, gas, turf, coal
