Machines Flashcards
A moment is sometimes known as a ______ force
Turning
How do u calculate a moment
Force is multiplied by the distance to the pivot
It’s exist in two directions, one in an _____ Direction and the other In a _____ direction
Anti-clockwise
Clockwise
When a system is _____ we can say that’s the Clockwise moment must equal the anticlockwise moment about the pivot
Equilibrium
Set moments must be equal so we can write:
force x distance (clockwise) = force x distance (anticlockwise)
Gears
gears can be used to transfer forces and motion from one object to another. Some gear systems can also be used to change the speed and direction of the motion.
Teeth
Gears have teeth on them that interlock with teeth from other gears. When teeth from two gears are in contact, we say they are meshed. When three or more gears are used together they are called a gear train.
How do gears turn
Gears turn on an axle, similar to a wheel.
What two things can a gear system change?
Speed
Direction
What type of gears meet at an angle
Bevel gears
What type of gear uses a screw?
Worm gear
How are gears and wheels similar?
Turn on axle
How are gears and wheels different?
Gears have teeth
If we turn the large gear around once, how many times will the small gear turn?
2
Would the small gear turn faster or slower than the large gear
Faster
If the small gear is turned twice, how many times would the large gear turn?
Once
Will the large gear turn faster or slower than the small gear?
Slower
How many times would you need to turn the small gear in order to make the large gear turn 7 times?
14
If GEAR 1rotates clockwise twice ,what will GEAR 2do?
Rotations- 4
Direction- anti clockwise
How does increasing the number of poly ropes affect the effort force
It reduces effort needed
Is there a relationship between the number of ropes and the ratio?If so what is it
Same I.e 2 ropes halves effort
What happens to the distance moved by the load compared to the amount of rope pulled by the effort force as the pulley systems get larger?
Less distance moved by load
As more pulleys and rope is introduced to the system what other force starts to have a larger impact on the efficiency of the system?
Friction
What is a pulley system
a force multiplier by increasing the number of ropes which support the load.
