Show:
Simple Machines
Levers
Wheels and Axles
Pulleys
Mystery
100
What is mechanical advantage?
Mechanical advantage is the measure of a machine’s usefulness or efficiency. -Or- How much advantage a machine is giving. -Or- The advantage of a machine.
100
What is a lever? (full definition is needed)
A lever is an object that has a rigid arm that turns around a point called a fulcrum.
100
How do you increase or decrease the MA of a wheel and axle?
You may increase the size (diameter) of the wheel or decrease the size (diameter) of the axle.
100
What are the three types of pulleys?
The three types of pulleys are single fixed, single movable and complex system of pulleys.
100
What is a fulcrum? (full definition is needed)
A fulcrum is a point that turns or pivots.
200
What is a simple machine?
A simple machine does not have an engine and uses 1 motion to do work.
200
What are the two main ways levers make work easier?
Levers can change the size and/or direction of force.
200
What is the mechanical advantage of the Wheel of Fortune wheel if the wheel has a radius of 3.2 meters and axle has a radius of .4 meters?
3.2/.4 = 8 The MA is 8.
200
Which pulley ONLY increases the size of the force input but does not affect the direction of the force?
The single movable pulley
200
Why does a longer input arm compared to an output arm create a greater output force?
It creates a greater output force because the arm spreads the force over a greater distance!
300
If a machine has an MA that is less than 1, what does that mean?
It means the machine will exert less force than what you put into it.
300
If the input arm is 15 meters and the output arm is 10 meters, what is the MA of the lever?
15/10 = 1.5 The MA is 1.5
300
The wheel’s radius is equivalent to the ____________ arm of a lever.
Input arm
300
If a 1600N load is being lifted on a single movable pulley, how much force is each rope supporting?
1600/2 = 800 Newtons
300
What is the rule of thumb when counting support ropes on pulley systems to calculate for MA?
Include the rope in your hand ONLY if it is being pulled up.
400
What is the MA of a machine with an Force Output of 27N and a Force Input of 8N?
27/8 = 3.375 The MA is 3.375
400
If the output arm is 30 meters and the MA is 4, what is the length of the input arm on a lever in meters?
30 x 4 = 120 m The length of the input arm is 120 meters.
400
What is the radius of an axle if its accompanying wheel is 240 cm and its MA is 4.8
240/4.8 = 50 cm The radius of axle is 30 centimeters.
400
If the weight is 80N, how much does each rope support? AND what is this pulley's MA?
80/2 = 40 Newtons per rope. This pulley has an MA of 2.
400
Which of the following is the most useful? 1) A lever with an input arm of 50 cm and an output arm of 100 cm. 2) A wheel and axle with an axle radius of 15 inches and a wheel radius of 45 inches. 3) Simple Machine “X” that requires an effort of 25 N to move a load of 50 N.
MA of Lever is .5, MA of Wheel and Axle is 3, MA of machine "X" is 2. WHEEL AND AXLE WINS!!!
500
What force is needed to lift a 487 N weight using a machine with a mechanical advantage of 5?
487/5 = 97.4 N The Force Input is 97.4 Newtons
500
Draw a Class 2 lever, label the three main parts, give one example.
Note: The benefit is that it always has a high MA because the input arm is longer than the output arm.
500
What is the full definition of a wheel and axle?
A wheel and axle are two disks or cylinders of different diameters mounted so they rotate together around the same axis.
500
1) Name that pulley. 2) What is the MA of this pulley? 3) If the weight is 525 Newtons, how much does each support rope hold?
It is a complex pulley system, MA = 5, Each rope holds 105 Newtons
500
Draw a Class 3 lever, label the three main parts, give one example and explain why it is useful even though it has a MA < 1.
It is useful because it allows for a range in motion.