6 FORM PACE WORK 16/04/20

6 FORM PACE WORK 16/04/20

                           

Тема: Прості машини

Read the words and find suitable definition for them:

1. inclined plane                          a) A simple machine consisting of a rigid bar pivoted on a fixed point and used to transmit force

2. machine                                 b) A device consisting of fixed and moving parts that modifies mechanical energy and transmits it in a more useful form.

3. pulley                                      c ) A wheel turned by or driving a belt.

4. wheel                                      d) A solid disk or a rigid circular ring connected by spokes to a hub, designed to turn around an axle passed through the center.

5. lever                                       e) A simple machine consisting of a rigid bar pivoted on a fixed point and used to transmit force, as in raising or moving a weight at one end by pushing down on the other.

Students do the task.

b) Teacher: Let’s prove your understanding of the words. Try to make your own sentences using these words.

4.2. Reading

There are 6 basic simple machines; the lever, the wheel and axle, the inclined plane, the wedge, the pulley, and the screw. Several of these simple machines are related to each other. But, each has a specific purpose in the world of doing work.

A lever is a stiff bar that rests on a support called a fulcrum which lifts or moves loads.

Levers are all around us. Some examples of levers are: door handles, the claws of a hammer (for removing nails), crowbars, light switches, bottle openers and hinges.

The wheel has always been considered a major invention in the history of mankind. But it really would not work as well as it does had it not been for the axle. An axle is a rod or pole centered in the wheel that allows the wheel to turn around it. The wheel then spins in a balanced circle to be used as transportation on a bike or to turn the hands of a clock. Gears are a form of the wheel and axle.

An inclined plane is a slanting surface connecting a lower level to a higher level.

Ramps are used in skateboard parks, wheelchair ramps and to get heavy equipment in and out of the back of trucks. But a modified version of a ramp is also found in stairs, escalators, ladders, walking paths, even chutes used for dropping your mail into the mailbox.

A wedge is an object with at least one slanting side ending in a sharp edge, which cuts material apart. Some examples of wedges that are used for separating might be a shovel, a knife, an axe, a pick axe, a saw, a needle, scissors, or an ice pick. But wedges can also hold things together as in the case of a staple, push pins, tack, nail, doorstop, or a shim.

A pulley is a simple machine that uses grooved wheels and a rope to raise, lower or move a load.

Pulleys are used in window blinds and drapery to move them up and down or back and forth.

The screw is really a twisted inclined plane. It allows movement from a lower position to a higher position but at the same time it moves it in a circle. That makes it take up less horizontal space. A screw can also act to hold things together in some cases.

Some examples of the uses of a screw are in a jar lid, a drill, a bolt, a light bulb, faucets, bottle caps and ball point pens. Circular stairways are also a form of a screw.

  

Teacher:  Make up questions to the text.

Teacher:  Answer the questions:

What is a simple machine?

Why do we need them?

What is a pulley? Examples

What is a lever? Examples

What is a wheel? Examples

What is a screw? Examples

What is a inclined plane? Examples

What is a Wedge? Examples

The purpose of a simple machine to make work easier by allowing for a push or pull to occur over an increased distance.

A: True

B: False

What is a simple machine that uses grooved wheels and a rope to raise, lower, or move a load?

A: lever

B: inclined plane

C: wheel and axel

D: pulley

What simple machine uses a wheel with a rod or rods through its center that will help it lift or move a load?

A: inclined plane

B: wheel and axle

C: screw

D: all of the above

What simple machine uses a slanted surface that connects a lower level to a higher level?

A: inclined plane

B: screw

C: wedge

D: lever

Which of the following would you use a pulley for?

A: hold pieces of plastic together

B: help guide a sail on a sailboat

C: cut food

D: all of the above

What type of simple machine is a seesaw on a playground?

A: inclined plane

B: pulley

C: wedge

D: lever

What type of a simple machine would the bottom of a light bulb be?

A: screw

B: wedge

C: lever

D: pulley

A fork would be an example of what type of simple machine?

A: pulley

B: wedge

C: lever