Understanding Simple Machines: Mechanisms and Applications
Posted on Nov 12, 2024 in Technology
Simple Machines
Mechanisms and Applications
- Which of the following machines can be considered a “complex machine?” Internal combustion engine
- What movement transmission mechanism is used on bicycles to rotate the shaft of the dynamo? Wheel friction
- Of the following arrangements, which item is easiest to raise? Hoist
- Which of the following levers reverses the direction of movement of the resistance to power? First-class lever
- In addition to a support (or frame), what other element is essential for a wheel to function properly? Axle or shaft
- Which of the following operators is not derived from the wheel? Connecting rod
- Which of the following machines does not use an incline in order to function properly? Piston
- Which of the following technical systems is not based on the lever? Train wheelbarrow rollers
- Which of the following mechanisms is not considered a sprocket? Lever
- Which of the following mechanisms is not derived from the screw? Rivet
- In a clothespin, what kind of levers are used? First and third class
- Which of the following is a machine that has mechanical advantage? Movable pulley
- What is the only lever that never has mechanical advantage? Third class
- When do you use a combination of fixed and movable pulleys in lifting or moving a mass? Hoist
- The movement to which the piston is subjected when inflating a balloon pump is: Reciprocating linear motion
- Which of the following speed multiplier pulley axes, “R” or “M”, moves faster? A
- If pulley “A” is attached to the motor, what name will it receive? Driver
- How many meters will the hook block “A” move up for every 2 meters of rope we pull down? 1 m
- Using a speed multiplier pulley, we want axis “B” to move twice as fast as “A”. If pulley “A” has a 100 mm diameter, what diameter should the pulley attached to axis “B” have? 50 mm
- If each box placed on the lever weighs 30 kg, which way will it tilt? Towards the B-side
- Which of the following objects uses a third-class lever? Clothespin
- If you weigh 40 kg, at what point will the fulcrum have to be placed to balance a friend who weighs 55 kg? At “C”
- How many meters will pulley “B” move up for every 2 meters of rope pulled down? 1 m
- What simple machines underlie the functioning of nail clippers? Lever and wedge
- In the pulley system of the figure, how fast does the driven shaft rotate if the driver rotates at 250 rpm? 500 rpm
- What will happen in the next system if “P” and “R” have the same mass? P will lower
- Which of the following techniques does not allow the transformation of rotational movement into linear movement? Gear train
- The following technical system is a lever on which 4 boxes of 20 kg each were placed. How does the system move? It will not move as they are
- The diagram below represents a steelyard. How much does the resistance weigh if the scales are balanced in this position? 2 kg
- Which operator is incorrectly placed to make the entire plane rotate around the next point? 2nd crankshaft
- The following mechanism is a pulley-belt transmission in which “A” is the driving pulley and rotates clockwise. Which other pulley also rotates clockwise? B
- The motor of a washing machine is attached to a pulley 8 cm in diameter, while the drum pulley is 32 cm. If the maximum motor rotation speed is 1500 rpm, what is the maximum rotation speed of the drum? 375 rpm
- If, in the previous question, the washing machine’s engine pulley is replaced with one twice the size, what will happen? The drum will spin slower
- In the rod-crank mechanism of the figure, what longitudinal distance (stroke) will the foot of the rod cover? 100 mm
- What mechanism would be installed inside the “black box” to produce these movements? Lever system
- With a 2.1 m fishing rod, a 2 kg fish is caught. What kind of lever is the fishing rod? Third class
- When holding the fishing rod at points “F” and “A”, what effort is required to lift the fish? 60 N
- If the hand position is the same, but a 4.9 m fishing rod is used, what effort would be required in that case? 28 N
- In the gear system of the figure, how fast does the pinion rotate when the wheel rotates at 250 rpm? 500 rpm
- In the previous gear system, in which direction will the pinion rotate? Counterclockwise
- What mechanism would have to be introduced in the black box of the figure to achieve the specified output motion from the rotary input? Eccentric rod
- The drawing shows a stepped pulley system belonging to a sensitive drill. Where should the belt be placed for maximum speed? On the two upper pulleys (d1 = 80 and d2 = 100)
- If the motor turns at 1400 rpm, what is the speed of the drill bit in its current position? 816.6 rpm
- If the motor turns at 1400 rpm, what is the minimum speed obtainable from the drill bit in the previous question? 600 rpm
- If we want the drill bit to turn at 1000 rpm with a 1400 rpm motor pulley, what pulley would be installed on the useful part? d2 = 112 mm
- In what direction will gear “C” turn in the gear train of the figure? Clockwise
- If the driving wheel rotates at 1250 rpm, what will be the speed of gear “B”? 2500 rpm
- What about gear “C”? 1666.6 rpm
- In the pulley train of the figure, what will be the speed of pulley “C” (80 mm in diameter) when pulley “A” rotates at 600 rpm? 2400 rpm
- And what speed will pulley “D” have when pulley “A” rotates at 600 rpm? 9600 rpm
- What mechanism can be installed inside the “black box” of the figure to obtain the indicated input and output movements? Rack and pinion
- Which of the following cams would have to be chosen to obtain the cam follower motion indicated in the graph? A
- In the following connecting rod-crank system belonging to an internal combustion engine of a car, if the piston has a stroke of 50 mm, how long will the crank arm be? 25 mm
- If the piston in the previous engine goes up and down 2400 times each minute, how fast does the crank turn? 2400 rpm
- With the indicated double wheel (Za = 16 and Zb = 8), the gear train of the figure has been built. If axis “A” rotates at 4000 rpm, what speed will axis “D” have? 500 rpm
- Which wheel moves faster? B
- Which wheel moves slower? A
- In which direction will wheel “C”, which is attached to the load, rotate? Clockwise
- If wheel “B” does not move any axis (shaft), what name is given to it? Idler
- Sort the wheels in descending order of speed (fastest, medium, slowest). B, C, A
- With a 4 m bar, we lift a 240 N butane bottle to a height of 250 mm using the lever mechanism shown. What kind of lever have we set up? First class
- What effort will have to be made? 60 N
- What will be the displacement of point “P” (where we apply the force) when the bottle is raised 250 mm from the ground? 750 mm
- How can we reduce the effort? By increasing the power arm
- A knife is a wedge with a handle, and when used to cut, it acts as a lever. What class of lever is it? Third class
- With the wheelbarrow in the figure, we want to carry a load of soil. By lifting the wheelbarrow, the point of application of force rises 240 mm. What kind of lever are we using? Second class
- How much does the load rise? (We consider it concentrated at point “R”) (Note the distance between the fulcrum and the point of application of force). 60 mm
- What effort do we have to make if the weight of the sand being transported is 1000 N? 250 N
- In the pulley train of the figure, what will be the speed of pulley “C” when pulley “A” rotates at 1000 rpm? 3000 rpm
- And how fast is pulley “D”? 12000 rpm
- A guitar has a mechanism that allows us to tighten the strings by turning a knob. What kind of mechanism is it? Worm gear
- In the figure of the previous question, how many turns do we have to make on the knob to get one turn of the drum that tightens the string? 16 turns
- What mechanism does a glue stick use to advance without staining? Screw and nut
- If the thread pitch of the glue stick mechanism is 3 mm, how many turns do we have to give the head to advance 2 mm of glue? 2/3 of a turn
- If we want the glue stick to move outward 20 mm with two turns of the head, what thread pitch would be necessary? P = 10 mm
- If the rack in the rack-pinion system of the figure moves in the indicated direction, what will happen to the pinion? It will rotate clockwise
- If the rack has 6 teeth per inch and moves 100 mm to the left, how many times will the pinion turn? Approximately 2.36 turns
- If the pinion rotates at 100 rpm, how fast will the rack move linearly? 200 mm/min or approximately 7.87 inches/min
- How fast does the pinion in the previous question have to rotate if we want to move the rack 200 cm in 30 seconds? 400 rpm
- How many teeth per inch must the rack have to advance 1 m for every 100 turns of the pinion? Approximately 39.37 teeth/inch
- The refrigerator compressor of a restaurant is driven by a pulley system. The driving pulley has a diameter of 6 cm and the driven pulley has a diameter of 24 cm. What is the velocity ratio? i = 4
- If the motor shaft in the previous question rotates at 1500 rpm, how fast does the compressor shaft rotate? N2 = 375 rpm
- On a children’s mountain bike, the chainrings have 45, 40, and 35 teeth, while the rear wheel sprockets have 28, 24, 21, 18, and 16 teeth. Which pairing provides the highest speed? 45-tooth chainring and 16-tooth sprocket
- On the bike in the previous question, if the cyclist pedals at a rate of 25 pedal strokes per minute (25 rpm), what will be the lowest speed obtainable on the wheel axis? 31.25 rpm
- If we pedal in the 45/28 gear ratio and the wheel has a diameter of 65 cm, how many meters will the bicycle advance per pedal stroke? 4.84 m
