Unit D

Question 1

What is a machine designed to do?

Answer 1

It helps us do work

Question 2

How do ancient machines pave the way for improvement?

Answer 2

We improved on previous models, we still do this day.

Question 3

What´s a simple machine?

Answer 3

A tool or device made up of one basic machine.

Question 4

Lever

Answer 4

A rigid bar or plank that can rotate on a fixed point called either a fulcrum or pivot.

Question 5

Examples of a lever

Answer 5

see-saw or scissors

Question 6

Inclined Plane

Answer 6

Flat, supporting surface tilted on an angle. One end it higher than the other.

Question 7

Example of Inclined plane

Answer 7

Ramp

Question 8

Wedge

Answer 8

Almost like an inclined plane, but it forced onto an object.

Question 9

Example of wedge

Answer 9

Knife

Question 10

Screw

Answer 10

A cylinder with grooves cut in a spiral on the outside.

Question 11

Example of screw

Answer 11

Archimedes screw

Question 12

Pulley

Answer 12

Wire, rope, or cable moving on a grooved wheel.

Question 13

Example of pulley

Answer 13

Flag

Question 14

Wheel and Axle

Answer 14

Combination of two wheels and a rod in between.

Question 15

Example of wheel and axle

Answer 15

Doorknob

Question 16

Classes of levers

Answer 16

1st class, 2nd class, and 3rd class

Question 17

Example of first class lever

Answer 17

see-saw

Question 18

Example of second class lever

Answer 18

wheel-barrel

Question 19

Example of third class lever

Answer 19

Fishing pole

Question 20

4 different effects of simple machine

Answer 20

• Changing direction of force
• Multiplying force
• Increasing or decreasing speed
• Transferring force

Question 21

Function of linkages

Answer 21

The linkage is the part that transfers energy between simple machines.

Question 22

Function of transmissions

Answer 22

A transmission contains a bunch of different gears. Transfers energy from motor to gears.

Question 23

The gear used in Mechanical devices are used for….

Answer 23

Changing speed and direction of machines

Question 24

Describe parallel gears

Answer 24

Equal sized circles with grooves cut all around.

Question 25

Describe multiplying gears

Answer 25

Larger gears (Driving gear) and a smaller gear (Driven gears).

Question 26

Describe reducing gears

Answer 26

Larger gears (Driven gears) and a smaller gear (Driving gears).

Question 27

What’s a mechanical advantage?

Answer 27

The amount of force applied to a machine.

Question 28

How to calculate mechanical advantage (MA)?

Answer 28

Output force divided by input force.

Question 29

What’s speed ratio?

Answer 29

Measure of how the speed of the object is affected by a machine.

Question 30

How to calculate speed ratio (SR)?

Answer 30

Input distance divided by output distance.

Question 31

Example of machine with a mechanical advantage of less than 1.

Answer 31

A bike

Question 32

How is efficiency calculated?

Answer 32

MA divided by SR multiplied by 100.

Question 33

What’s the scientific definition of “work”?

Answer 33

Done when force acts on an object to make the project move.

Question 34

What effect does friction have on a machine?

Answer 34

Friction effects a machines efficiency.

Question 35

How is “work” calculated?

Answer 35

Force exerted multiplied distance.

Question 36

What did first machines depend o to work?

Answer 36

Humans and animals

Question 37

To move water, the Archimedes _____ was designed.

Answer 37

Screw!

Question 38

The two basic machines used in scissors are…..

Answer 38

wedge and lever

Question 39

Gears are made up of flat, toothed disk called…

Answer 39

sprockets

Question 40

How to calculate pressure?

Answer 40

Force divided by area

Question 41

Describe input force and output force.

Answer 41

The amount of force you put into an object is the input force, and the amount of force the object put into another object is output force.

Question 42

Hydraulic system?

Answer 42

A system that uses liquid under pressure to move loads.