science- mechanical systems

Question 1

What is a lever and what are the key parts

Answer 1

A simple machine that changes the amount of force you must exert on an object

• the fulcrum, load and effort

Question 2

what is the fulcrum

Answer 2

fulcrum- the point of the lever that does not move

Question 3

class 1, 2 and 3 + examples

Answer 3

1- a lever in which the fulcrum is between the load and effort ex: seesaw
2- a lever in which the load is between the fulcrum and effort ex: wheelbarrow
3- a lever in which the effort is in between the load and fulcrum

Question 4

what is an inclined plane

Answer 4

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

Question 5

what is ergonomics + example

Answer 5

The science of designing machines to suit people, usually for comfort, safety or support ex- desk chair

Question 6

what is a winch

Answer 6

a simple machine that consists of a small cylinder, a crank and a cable which is used for lifting

Question 7

what is a wheel and axle + example

Answer 7

a simple machine consisting of two objects attached to each other at their centre, one object causes the other to turn. ex: bike

Question 8

what is MA

Answer 8

The ratio of the force produced by a machine to the force applied to the machine

the ratio of work done by the machine to the ratio of work done on the m

Question 9

input vs output work

Answer 9

input- work on a machine
output-the work a machine does on a load

Question 10

what are gears and gear trains

Answer 10

gear- a rotating wheel like device with teeth around its rim
gear train- a group of two or more gears that are meshed together

Question 11

what are the driver and follower gears

Answer 11

driver- the main gear that causes the other gears to move
follower-a gears whose movement is caused by the driver gear

Question 12

what is a sprocket + example

Answer 12

a gear with its teeth that fit into the links in a chain ex: bike

Question 13

what are the load and effort arm

Answer 13

load arm- the distance between the fulcrum and the effort force
effort arm- the distance from the load to the fulcrum

Question 14

what is a pulley + example

Answer 14

a wheel with a grooved rim to guide a rope or chain that runs along the groove example- elevator

Question 15

what is speed ratio

Answer 15

The relationship between the speed of rotations of smaller gears and larger gears

Question 16

fixed vs movable pulleys and what are the MAs for them

Answer 16

fixed- a pulley supported by a attachment to something that doesn’t move MA= 1

Movable- a pulley attached to something movable MA= 2

Question 17

compound pulley

Answer 17

a combination of multiple pulleys working together

Question 18

block and tackle pulley

Answer 18

a combination of fixed and movable pulleys

Question 19

kinetic energy + example

Answer 19

the energy of motion example- throwing a ball

Question 20

potential energy

Answer 20

stored energy ex: being at the height of a roller coaster

Question 21

what is energy transmission

Answer 21

energy is transferred from one place to another and is changed or converted

Question 22

what causes a machine to lose efficiency and what can be done to avoid it

Answer 22

efficiency is lost from friction you can use lubricants to try to reduce the energy lost

Question 22

what is efficiency

Answer 22

a comparison of the useful work by a machine or system with work supplied to the machine or system

Question 23

what is a load

Answer 23

the weight of the object that is moved or lifted

Question 24

what is the effort force

Answer 24

the force supplied to any machine to produce action

Question 25

what is the relationship between force, pressure, and area

Answer 25

pressure is the measurement of the amount of force applied to a given area

Question 26

what is pascals law

Answer 26

pressure is applied to enclosed fluid that is transported

Question 27

what is pressure

Answer 27

the force acting perpendicular to a certain surface area

Question 28

what is a hydraulic lift

Answer 28

a mechanical system that uses a liquid under pressure in a closed system to raise heavy objects

Question 29

what is a closed system

Answer 29

a system having a boundary that separates it from its surroundings

Question 30

What are hydraulic systems? + examples usually supplied by a motor

Answer 30

a device that transmits an applied force thorough a liquid to move something else example- car jack, elevator

Question 31

what is a pneumatic system + examples a open system

Answer 31

a system in which a gas transmits a force exerted on the gas in a enclosed space ex: jack hammer, drills

Question 32

what is a complex machine think of Goldberg machines

Answer 32

several simple machines all working machines working together in a system

Question 33

what is a system

Answer 33

a group of parts that work together to preform a function

Question 34

subsystem

Answer 34

a simple machine that works in a larger system

Question 35

what are the six simple machines and which are the parents

Answer 35

Lever* Wheel and Axle Pulley Inclined Plane* Wedge Screw

Question 36

what is a steam engine

Answer 36

fuel is burned to heat water in a boiler outside of the engine the water turns to steam and powers the engine

Question 37

what is a piston

Answer 37

a movable disc that fits inside a cylinder to help move an object

Question 38

what is a exhaust valve

Answer 38

in a engine a movable part that controls the amount of escaping in a cylinder

Question 39

what is a turbine

Answer 39

a rotary mechanical device that extracts energy from a fluid flow

Question 40

what is a internal combustion machine

Answer 40

a type of engine in which fuel in burned internally

Question 41

what is mass production

Answer 41

the making of large quantities in a standard process

Question 42

what is a hydrogen fuel cell

Answer 42

a cell that fuels a chemical reaction that uses hydrogen and oxygen to make electricity