INCOMPLETE Grade 8 Unit D Test (Section 1)

Question 1

What is a machine?

Answer 1

A device that helps us do work

Question 2

What is a simple machine?

Answer 2

A tool or device made of one basic machine

Question 3

What are the 6 simple machines?

Answer 3

Levers, pulleys, inclined plane, screw, wedge, and wheel and axle

Question 4

What is a lever?

Answer 4

A rigid bar or plank that rotates on a fixed point called a fulcrum or pivot

Question 5

What is a lever used for?

Answer 5

Reducing the force needed to move a larger load

Question 6

What are the types of levers?

Answer 6

First class, second class, third class

Question 7

What is a first class lever?

Answer 7

A lever in which the fulcrum is in the middle and where the effort is on one side and the load is on the other

Question 8

What are some examples of a first class lever?

Answer 8

A seesaw, scissors, and pliers

Question 9

What is a second class lever?

Answer 9

A lever in which where the load is in the middle, the effort on one side, and the fulcrum is on the other side.

Question 10

What is an example of a second class lever?

Answer 10

A wheelbarrow, a nutcracker, and a bottle opener

Question 11

What is a third class lever?

Answer 11

A lever in which the force is in the middle, the fulcrum is on one end, and the load is on the other end

Question 12

What is an example of a third class lever?

Answer 12

Hammer, hockey stick, rake

Question 13

What is an inclined plane?

Answer 13

A simple machine made up of a flat surface at an angle to another flat surface

Question 14

What are inclined planes used for?

Answer 14

Inclined planes are used to lift heavy objects with a smaller force but he force is exerted over a larger distance

Question 15

What are some examples of inclined planes?

Answer 15

Ramps, a slanted roof, a slanted driveway

Question 16

What is a wedge?

Answer 16

A simple machine similar in shape to an inclined plane but is forced into an object

Question 17

What are some examples of a wedge?

Answer 17

An axe, a door wedge, a knife

Question 18

What is a screw?

Answer 18

A cylinder with a groove cut in a spiral on the outside. Can penetrate materials with relatively small force, they can move materials slowly (cement truck)

Question 19

What are some examples of a screw?

Answer 19

A screw (used in building), a light bulb, and a bottle cap

Question 20

What is a pulley?

Answer 20

A system of a wire, rope or cable moving on a grooved wheel. It is used to lift objects while the operator is pulling down

Question 21

What are some examples of a pulley?

Answer 21

Cranes, flag poles, and window blinds

Question 22

What is a wheel and axle?

Answer 22

A combination of two attached wheels of different diameters that turn together

Question 23

What are some examples of a wheel and axle?

Answer 23

Car tires, a bicycle, a ferris wheel

Question 24

What are complex machines?

Answer 24

Systems where simple machines work together

Question 25

What is a system?

Answer 25

A group of parts that work together to perform a general function

Question 26

What is a subsystem?

Answer 26

A smaller group of parts in a complex machine that perform a specific function. Normally has a simple machine

Question 27

What is linkage?

Answer 27

A belt or chain that transfers energy from and energy source to an object

Question 28

What is transmission?

Answer 28

Basically linkage but only for transferring the energy from the engine to the wheels of large vehicles.

Question 29

How do gears work in transmissions?

Answer 29

On low gear, the wheels rotate slower than the engine does. On high gear, the wheels rotate faster than the engine does.

Question 30

What are gears?

Answer 30

A pair of wheels with teeth that interlink. When one rotates, it transfers turning motion and force to the other. . They control the transfer of energy in a system.