Unit 4

Question 1

Whats in the middle in a class 1 lever?

Answer 1

Fulcrum

Question 2

Whats in the middle in a class 2 lever?

Answer 2

Load

Question 3

Whats in the middle in a class 3 lever?

Answer 3

Effort

Question 4

What advantage does a class 1 lever give?

Answer 4

Power

Question 5

What advantage does a class 3 lever give?

Answer 5

Speed

Question 6

What is the unit for work?

Answer 6

Joules

Question 7

1 Newton is approximately the weight of ____g

Answer 7

100

Question 8

What is an inclined plane?

Answer 8

A ramp or slope for reducing the force needed to lift something

Question 9

What is mechanical advantage?

Answer 9

The ratio of force produced by a machine or system (the load) to the force applied to the machine

Question 10

What is the formula for MA?

Answer 10

Load force/Effort force

Question 11

What is the advantage if MA is over 1?

Answer 11

Power

Question 12

What is the advantage if MA is under 1?

Answer 12

Speed

Question 13

What is the advantage if MA equals 1?

Answer 13

Change of direction

Question 14

What is ergonomics?

Answer 14

The science of designing home or work environments that best suit human needs

Question 15

What is a winch?

Answer 15

A machine consisting of a small cylinder, a crank or handle, and a cable, used for lifting and pulling.

Question 16

What is and example of a winch?

Answer 16

Handle of pencil sharpener, Reel of fishing rod

Question 17

What MA does a winch give you?

Answer 17

Power

Question 18

What is a wheel and axle?

Answer 18

A machine consisting of two turning objects attached to each other at their centers, one object causes the other to turn

Question 19

What is an example of a wheel and axle?

Answer 19

A winch

Question 20

What are some subsystems in a bicycle?

Answer 20

Wheel and axle
Gears-Sprocket system
Pedals-Lever
Brakes-lever

Question 21

Define gear

Answer 21

A rotating wheel like device with teeth around its rims

Question 22

Define gear train

Answer 22

A group of two or more gears that are meshed together

Question 23

What is the opposite of a gear train?

Answer 23

A sprocket system

Question 24

What is a multiplying gear?

Answer 24

When a large gear drives a smaller gear-increases speed and decreases torque

Question 25

What is a reducing gear?

Answer 25

When a small gear drives a larger gear-increases torque and decreases speed

Question 26

What is it called when two gears are the same size?

Answer 26

Parallel gears

Question 27

What are the four types of pulleys?

Answer 27

Fixed-doesn't move Movable-moves with the load Block and tackle-combination of movable and fixed Compound-one or more pulley together

Question 28

How do you calculate MA of a pulley?

Answer 28

Count all the ropes except ones you pull down on

Question 29

Define potential energy

Answer 29

Stored energy

Question 30

Define kinetic energy

Answer 30

the energy of motion

Question 31

Define transmission

Answer 31

Energy is transferred from one place to another and no energy is changed or converted

Question 32

What does it mean to transfer energy?

Answer 32

To change the type of energy

Question 33

What is efficiency?

Answer 33

The ratio of work energy provided by a machine or system with the actual work or energy supplied to the syetem

Question 34

How can efficiency be boosted?

Answer 34

- Cleaning - Lubricating - Keep tires inflated

Question 35

What are useful examples of friction?

Answer 35

Bike tires against the road rosin winter tires track spikes

Question 36

What is the unit of pressure?

Answer 36

Pa (Pascals)

Question 37

What is Pascal's law?

Answer 37

If pressure is applied to a fluid, i will spread out equally in all directions in the shape of the container in a closed system

Question 38

What is a hydraulic system?

Answer 38

A device that transmits an applied force through a liquid to move something else by means of pressure.

Question 39

Is hydraulics open or closed?

Answer 39

Closed

Question 40

What is a hydraulic system in the human body?

Answer 40

The heart

Question 41

What is a pneumatic system?

Answer 41

A system in which gas such as air transmits a force exerted on the gas in an enclosed space

Question 42

Is pneumatics open or closed ?

Answer 42

Open

Question 43

What is a pneumatic system in the human body?

Answer 43

lungs

Question 44

Why are subsystems combined into more complex machines?

Answer 44

It makes them more efficient

Question 45

How have machines changed throughout history

Answer 45

Machines have become more efficient and work better-ergonomics

Question 46

How does a steam engine work?

Answer 46

Water is heated steam is pressurized used to make a piston move the piston is attached to a rod to move engine

Question 47

Why is steam used instead of water?

Answer 47

Water would expand and evaporate too heavy can't be compressed

Question 48

What is a piston?

Answer 48

A disc shaped part that fits tightly inside a cylinder in which some force, such as steam pressure, moves it back and forth or up and down

Question 49

What is an internal combustion engine?

Answer 49

A type of engine in which fuel is burned internally

Question 50

What are the fours strokes of an internal combustion engine?

Answer 50

Intake stroke-air is brought in Compression stroke-fuel is mixed with air and compressed Power-A spark ignites the fuel Exhaust-Excess air and fuel go out a valve