Mechines Final

Question 1

What is a simple machine

Answer 1

It tool or device made up of one basic machine

Question 2

What are the advantages and disadvantages of a lever

Answer 2

Advantage you can move a much larger load than by hand. Disadvantages, you must move a greater distance than the load does

Question 3

What are the advantages and disadvantages of a pulley

Answer 3

Advantages: you can lift heavy loads, you can take things straight up while pulling down
Disadvantages, it takes a lot more time to pull up a load that has been lightened (by the MA)

Question 4

What are the three classes of levers

Answer 4

The first is where thefulcrum is in between the resistance force and the effort. A second-class lever is where the resistance force is in between effort and the fulcrum. A third class lever is when the effort force is in between the fulcrum and the resistance force

Question 5

What is mechanical advantage

Answer 5

The amount by which a machine can multiply force

Question 6

How do you calculate actual mechanical advantage

Answer 6

MA=output force
————–
input force

Question 7

How do you calculate the ideal mechanical advantage of a lever

Answer 7

length of resistance arm

Question 8

How do you calculate the ideal mechanical advantage of a pulley

Answer 8

Count the supporting strings

Question 9

What is the ideal mechanical advantage of a wheel and axle

Answer 9

The radius of the wheel divided by the radius of the axle

Question 10

What is the ideal mechanical vantage of an inclined plane

Answer 10

height of ramp

Question 11

What is speed ratio

Answer 11

A measure of how the speed of the object is affected by a machine

Question 12

I how do you calculate speed ratio

Answer 12

output distance

Question 13

What is efficiency

Answer 13

A measure of how well a machine uses/converts energy

Question 14

How do you calculate efficiency

Answer 14

MA
—- x 100
SR

Work output

Question 15

What is a complex machine

Answer 15

A system in which simple machines all work together

Question 16

What are the six simple machines

Answer 16

Lever inclined plane wedge screw pulley wheel and axle

Question 17

What are hydraulics

Answer 17

A hydraulic system uses a liquid under pressure to move loads

Question 18

What is pascals law?

Answer 18

When pressure is applied to a liquid in a container pressure and force is transmitted equally throughout the liquid

Question 19

What is one pascal?

Answer 19

The force of one Newton over an area of 1m2

Question 20

What I the difference between the input and output Pistons?

Answer 20

The input piston is used to apply the force to the liquid which created pressure in the fluid. The output piston applies force to move load

Question 21

What provides the MA in hydraulic systems?

Answer 21

The fluid pressure

Question 22

What do hydraulic systems allow?

Answer 22

You to use a smaller force on a smaller piston to produce a large force on a large piston

Question 23

Give an example of how to calculate pressure in hydraulic systems

Answer 23

Fin Fout
—- = —–
Ain Aout

Cross multiply and divide

Question 24

What is the cost of the mechanical advantage of hydraulic systems?

Answer 24

The smaller input piston must move a greater distance to increase the force on the larger output piston

Question 25

What is the difference between effective and efficient?

Answer 25

Effective is does it complete the task or do the job? Efficient is how well it can do that. Efficiency can relate to time, environmental reasons, storage etc.

Question 26

How do you calculate work?

Answer 26

Work is calculated by Force x Distance

Question 27

How do you calculate the efficiency of something?

Answer 27

``` You devide MA ----- x 100 SR Or work input ------------ Work output And no matter what the equation says to do, always put the smaller number over the bigger number because your efficiency cannot be more than 100% ```

Question 28

What are the units for work?

Answer 28

Jules (J)

Question 29

What is the units for efficiency?

Answer 29

Percentage (%)

Question 30

What is the units for force?

Answer 30

Newtons (N)

Question 31

What is the units for MA?

Answer 31

Nothing, it has no unit

Question 32

What is the units for distance?

Answer 32

Meters (M)

Question 33

What is classified as work?

Answer 33

When you move something from one place to another

Question 34

What are the advantages and disadvantages of a screw?

Answer 34

Advantages:it helps you increase the force you use. It can penetrate materials by using a relatively small force Disadvantage: screws move objects very slowlyy

Question 35

What are the advantages and disadvantages of a wheel and axle?

Answer 35

Advantages:The wheel and axle multiplies your power or increase the size of your force Disadvantage: you have to turn a greater distance (large wheel) to apply the force

Question 36

What are the advantages and disadvantages of an inclined plane?

Answer 36

Advantages: makes it possible to lift heavy objects using a smaller force Disadvantage: you have to exert the force over a greater distance than by just lifting it up. When the ramp is steep it's hard to control the motion of the object

Question 37

What are the advantages and disadvantages of a wedge?

Answer 37

Advantage:it increases the force that you apply to the object Disadvantage: the wedge can only be used in one direction (to push the objects apart)

Question 38

What does work input and work output mean?

Answer 38

Work input is the work done by you (lifting something by hand) Work output is the work done by the machine (lifting something with a pulley)

Question 39

What is the difference between multiplying an reducing gears?

Answer 39

A multiplying Gera is when the big gear is the motor and the small gear is the driven gear (more speed less power) A reducing gear is when the small wheel is the motors and the big gear is the driven gear (less speed more power)

Question 40

How does friction effect efficiency

Answer 40

All machines lose some energy as it is used. Energy is usually lost as heat due to friction. The more energy that is lost the less efficient the machine

Question 41

What is the difference between function and design

Answer 41

Function is what it object is supposed to do and the design is the shape of an object that makes it usable. Do you have to make sure that the design fits the function