Calculations
Simple Machines
Complex Machines
Work and Pressure
Calculations
100
If you have a hydraulic system and you input 75N over an area of 5m2. What is the pressure?
15Pa
100
What is a simple machine?
A machine made of one basic machine
100
How do machines make humans life easier?
Machines multiply the force that humans input into a machine which is what mechanical advantage refers to
100
What is pressure measured in?
Pascals
100
What is the amount of work done when a man pushes a box 2m using 150N?
300J
200
What is the mechanical advantage of a machine that has an input force of 147N and a output force of 384N?
2.6
200
Draw a diagram of a lever (any class) and label the parts
200
Draw a hydraulic system.
Label the input piston, output piston, input force, output force
Mr. Murphy is the judge
200
What is work measured in?
Joule
200
What is the speed ratio of a lever when a man pushes down one side 4m the other side goes up 1.5m?
2.7
300
A man sitting on a bench exerts a force of 500N on the ground with a pressure of 250Pa, how much work was done?
None - needs distance
300
What is a disadvantage of a double wheeled pulley?
You need to pull the load twice the distance
300
What is a linkage? Give an example.
Linkage is a part of a complex machine that transfers the force from one part to another (i.e. bike chain)
300
What are the two conditions for work to be done?
Force and Distance
300
What is the pressure created when a hammer hits a nail with 450N of force is exerted on 1500cm2?
3000Pa
400
If a machine is 24% efficient, what % of energy is lost as heat?
76%
400
How does a simple machine increase speed?
By requiring a higher input force than output. Therefore decreasing force
400
What is a reducing gear?
Gear that decreases the turning speed in a device
400
What is Pascal's law?
Pressure in an enclosed system is applied equally in all directions
400
I have cities, but no houses. I have mountains, but no trees. I have water, but no fish. What am I?
A Map
500
What is the force needed to move a rubber duck 15m using 350J of work?
23.3N
500
You see a boat filled with people. It has not sunk, but when you look again you don’t see a single person on the boat. Why?
All the people were married.
500
Why would a machine have a mechanical advantage of less than 1?
Because by decreasing the mechanical advantage you increase the speed
500
What is a big misconception people have about machines and work?
Machines do not decrease the amount of work they decrease the amount of force
500
A woman exerts a force of 165N on a piston with an area of 2000cm2 to lift an elephant that is on a larger piston with an area of 30000cm2. What is the force that was needed to lift the elephant? Make sure to convert to meters.
2475N