3º NS Unit 6 – MACHINES AND INVENTIONS (Student´s Book and Activity Book SOLUTIONS)

HOMEWORK:

1. Please, check the solutions to the exercises you did this week from the books of N.S. 
(Student´s Book and Activity Book).

UNIT 6 Natural Science – MACHINES AND INVENTIONS

3º NS STUDENT´S BOOK (solutions)

PAGE 98

SOLUTIONS

1 Petrol. Today we use petrol, diesel or electricity.

2 The Wright brothers. It could fly for 30 minutes.

3 Pupils' own answers.

PAGE 99

SOLUTIONS

4 The telegraph.

5 Morse Code.

6 Pupils' own answers.

PAGES 100, 101

SOLUTIONS

1 – Answers:

a. 1.pencil sharpener; 2.swivel chair; 3.scissors; 4.pulley; 5.slide; 6.roller skates; 7.pizza cutter; 8.tap.

b. 1.screw; wedge, 2.wheels, screws, lever; 3.screw, wedge; 4.pulley, wheels, screws; 5. inclined plane, screws; 6. wheels, screws; 7.wedge, screw, wheel; 8.screw.

2 Pupils' own answers.

3 a. car, for transport; horse and carriage; b. washing machine, for washing clothes; People in the past used to wash their clothes in rivers.

4 Fridge, for storing food safely, (electricity); microwave, for reheating food safely, (electricity); washing machine, for cleaning fabric, (electricity and water); vacuum cleaner, for cleaning surfaces, (electricity); cooker, for cooking food safely, (electricity or gas).

5 Pupils' own answers.

6 Pupils' own answers.

7 Pupils' own answers.

PAGES 102, 103

SOLUTIONS

1 – Answers:

SIMPLE MACHINES: pulley, lever, wedge, screw, inclined plane, wheel and axle.

COMPLEX MACHINES: transportation and communication.

Transportation: bicycle, car, steam train.

Communication: telegraph, telephone, smartphone,

2 - a.pulley - b.lever - c.screw

3 - c.the drill

4 - a.the telegraph, communication - b.telephone, electrical - c.lever, bicycle - d.steam engines, industrial.

5 - Answers from left to right are: steam engine; 1804; telegraph; 1876; car; 1903; smartphone.

6 -

Pupil A

a. What is a complex machine made up of? (Simple machines)

b. What started the transport revolution? (Steam engine and steam trains)

c. Who invented the telephone? (Alexander Graham Bell)

Pupil B

a. What is a simple machine? (A machine with no or few moving parts)

b. Do all complex machines use electricity? (No, they don't.)

c. What is a pulley used for? (Lifting and lowering objects)

3º NS ACTIVITY BOOK (solutions)

PAGE 35

SOLUTIONS

8 – a. communication revolution – b. aeroplane – c. steam engine – d. car – e. smartphone – f. telegraph – g. train – h. Morse code.

9 – Answers: 2. This is a fridge. It is used for keeping food cold. – 3. This is a microwave. It is used for heating food. – 4. This is a washing machine. It is used for cleaning clothes. – 5. This is a vacuum cleaner. It is used for cleaning the floors.