2.2.2 Flashcards
what is velocity ?
change in displacement over time
when is the one time that acceleration remains constant ?
when caused by earths gravitational attraction
whats the gravitational acceleration on earth ?
9.8m/s
what is a pendulum ?
wire attached to pivot point with weighted ball which swings freely under gravity
does mass of weight / bob on pendulum make a difference to the periodic time ?
no
does the length of the pendulum make a difference in the periodic time ?
yes
what is damping forces ?
resistance on the body which reduces the amplitude such that after a while, the body will come to a stop
what does damping decrease ?
vibrations
what is the definition of vibration ?
mechanical oscillations
whats the 4 types of vibration ?
-free vibration
-forced vibration
-harmonics
-resonance
what is the lowest frequency of a periodic waveform called ?
fundamental frequency
what is velocity ratio ?
its how far the effort has to move in relation to the load
whats the mechanical advantage ?
ratio of the force produced by a machine to the force applied to it
whats 3 examples of a first class lever ?
-seesaw
-crowbar
-claw hammer
where is the fulcrum located on a second class lever and whats a example ?
-located at one end of the lever
-wheel barrow
where is the effort applied located on a third class lever ?
between the fulcrum and the resistance load
whats a example of a third class lever ?
aircraft landing gear
explain a incline plane and say a example of one ?
-surface inclined to a horizontal plane at any angle but a right angle.
-baggage conveyor
whats the equation for horsepower ?
torque x rpm
——
5252
what is efficiency measured in ?
percentage
