Kinetics Flashcards
What does XUVAT stand for?
x=displacement u=initial velocity v=final velocity a=acceleration t=time
Equations of xuvat?
1) v= u + at
2) x= 1/2 * (u+v)t
3) x= ut + 1/2*at^2
4) v^2= u^2 + 2ax
What is acceleration due to gravity?
9.81 m/s^2
What are the two forces in rotational movement?
Centrifugal
Centripetal
What is centrifugal force?
Centrifugal force pulls AWAY from the center
What is centripetal force?
Centripetal force pulls TOWARDS the center
Centripetal force equation
Centripetal force = (mv^2)/r
m=mass
v=velocity
r=radius
What is the link between the centripetal force and radius?
The bigger the radius, the smaller the force
What is the centripetal acceleration equation?
Centripetal acceleration = v^2/r
What does a pendulum depend and not depend on?
Depends in the length of the string NOT on the mass
What is the periodic time?
Time it takes to complete one oscillation
What is damping?
The resistive force that slows down the swing/reduces the amplitude of the swing
What forces can be used for damping
Air resistance
Friction
What are the 2 types of vibrations
Free vibrations
Forced vibrations
What is the definition of vibrations
The mechanical oscillations about an equilibrium force
Velocity (speed) Ratio equation
Distance moved by effort / distance moved by load
Distance in/ distance out
Ideal mechanical advantage equation
Distance in / distance out
Actual mechanical advantage equation
Force out / force in
Mechanical advantage equation
Resistance / effort
How many classes of levers are there?
3 classes
How do you calculate the effort in Levers?
L x E = R x l
L= length (effort arm) E= effort R= resistance l= length (resistance arm)
What is the difference between class 1 and 2 levers?
The position of the fulcrum on a class 1 lever leaves an arm on either side (see-saw) Class 2 - the position of the fulcrum is on the edge of the lever (wheelbarrow)
What is a class 3 lever ?
Class 3 levers are primarily used to move greater distances than effort applied. It applies the effort between the fulcrum and resistance
On a pulley, if you have more supoorting ropes what does that mean for the Mechanical Adavantages?
More MA
What types of gears are there?
Spur gears
Bevel gears
Worm gears
Sun+Planetary Gears
Characteristic of a spur gear
Used to connect 2 parallel shaft
Bevel gears characteristics
Drive shaft and driven shaft are not parallel
Worm gear characteristics
Used when an extreme amount if mechanical advantage is needed
Sun + planetary gear characteristics
Reduce propeller shaft speed on a more powerful engine
What has more Mechanical Advantage - class 1 or. 2
Both have the same mechanical advantage
2 equations for efficiency
Efficiency = work in / work out x 100
Efficiency = mechanical advantage / velocity ratio
