content dump Flashcards
What are the three main components of all lever systems?
LOAD, FULCRUM (PIVOT), EFFORT
These components are essential for understanding how levers function.
What is the formula for calculating Moment?
Moment = Force (N) x Distance (m)
This formula is used to determine the turning effect of a force about an axis.
What is a moment measured in?
Newton-meters (Nm)
This unit quantifies the turning effect produced by a force.
How do you rearrange the formula to find the required force?
Force (N) = Moment (Nm) / Distance (m)
This rearrangement is useful for calculating input force when the moment and distance are known.
What is the Law of Levers?
A lever is balanced when the weight on one side multiplied by its arm length equals the weight on the opposite side multiplied by its arm length.
This law helps in understanding how levers maintain equilibrium.
True or False: Torque is the same as moments.
True
Both terms refer to the measure of force that can cause an object to rotate about an axis.
What is the SI unit for torque?
Newton-meters (Nm)
This unit is used internationally to measure torque.
Fill in the blank: A moment is the product of _______ and _______.
Force (N), Distance (m)
This relationship is crucial for calculating moments in various scenarios.
List two examples of single levers.
- Crowbars
- Spanners
Single levers have the load, fulcrum, and effort aligned in one line.
List two examples of pairs of levers.
- Pliers
- Tweezers
Pairs of levers consist of two levers working together to enhance mechanical advantage.
What happens to the input force if the length of the lever is increased while keeping the moment constant?
The input force must be less
This principle illustrates how levers make tasks easier by increasing their length.
What does the term ‘torsion’ refer to?
The twisting force
Torsion is related to torque and describes the force that causes rotation.
What is the effect of multiple weights at multiple distances on a lever?
They can be added together on either side of the fulcrum
This concept is important when analyzing complex lever systems.
What is the moment created by a 50kg child sitting 0.5m from the fulcrum?
25Nm
This is calculated using the formula Moment = Force x Distance.
Calculate the moment created by a force of 400N acting at a distance of 0.5m.
200Nm
This illustrates the application of the moment formula.
What is the result of balancing the moments on both sides of a lever?
The system is in balance
Equilibrium is achieved when moments are equal on both sides.
What is the twisting force that causes an object to rotate about an axis called?
Torque
Torque is a crucial concept in mechanics and engineering.
What is the purpose of learning about Pulley Systems?
To demonstrate an understanding of Mechanical Advantage, Velocity Ratio and Efficiency of pulley systems.
What are the three key concepts to describe in pulley systems?
- Mechanical Advantage
- Velocity Ratio
- Efficiency
How is Mechanical Advantage (MA) defined in a pulley system?
The number of ropes supporting the load.
What is the Mechanical Advantage of a pulley system that is designed to require less effort to lift an object?
2:1
What is the relationship between Mechanical Advantage and lever systems?
They can have similar Mechanical Advantages.
What is the Velocity Ratio (VR) in a pulley system?
The distance the rope must be pulled compared to the distance the load is lifted.
If a pulley system has a Mechanical Advantage of 4, how much further must the rope be pulled compared to the load lifted?
4 times further.
How is efficiency calculated in a pulley system?
Efficiency = MA ÷ VR x 100%
What is the efficiency of a pulley system with MA = 4 and VR = 4?
100%
What factors can affect the efficiency of a pulley system in practice?
- Poor design
- Incorrect assembly
- Uneven loading
- Friction
- Wear
- Deformation
True or False: The efficiency of a pulley system can be greater than 100%.
False
Name three types of gears.
- Worm & Gear
- Bevel Gears
- Spur Gears
What type of motion can a Rack and Pinion system change?
Rotary to Linear.
What is the Driver Gear?
The gear on the input shaft.
What is the Driven Gear?
The gear on the output shaft.
How are gears represented in technical drawings?
By drawing two circles that overlap where teeth mesh.
In a Worm & Gear system, which gear is always the Driver?
The Worm.
What is the gear ratio for a Worm & Gear system?
Number of teeth on the Driven Gear / 1.
What does a high gear ratio indicate?
Less speed, more torque.
What does a low gear ratio indicate?
More speed, less torque.
What is a Compound Gear Train?
A system that involves several pairs of meshing gears.
What is required for a system to be classified as a Compound Gear Train?
Must have multiple gears on an axle.
How is the total gear ratio calculated for Compound Gear Trains?
Total Gear Ratio = GR1 x GR2.
What is the formula to calculate the Output Speed?
Output speed = input speed ÷ velocity ratio (gear ratio).
If the input speed is 1000 rpm and the gear ratio is 4:1, what is the output speed?
250 rpm.
How can you convert Rotary Motion into Linear Motion?
Using a Rack and Pinion system.
Fill in the blank: The gear ratio formula is GR = _______.
Teeth Driven ÷ Teeth Driver.
True or False: In a non-compound gear train, idler gears affect the total gear ratio calculation.
False.
What is the result of a gear ratio of 5:1?
The output is 5 times slower than the input.
What is the application of a Worm & Gear system in vehicles?
Used in the steering system of a tractor.
What happens to the Driven Gear when the Worm Gear completes one revolution?
Advances the Driven Gear by one tooth.
