Balbharati solutions for जनरल साइंस इंटेगरटेड [अंग्रेजी] कक्षा ६ महाराष्ट्र राज्य बोर्ड chapter 12 - Simple Machines [Latest edition]

In the following pictures, certain devices are used to accomplish certain tasks more easily. Name the devices and discuss how they help.

Observe the machines shown in the following pictures. For what purposes are they used? Can you name some? other machines of this kind?

A heavy drum is to be loaded onto a truck. Ravi chose the plank A while Hamid chose the plank B. Rahi did not use a plank at all.

1. Who would find the drum heaviest to load?
2. Who would find it lightest?

Which one of the planks A and B is longer?

 Which one has a steeper slope?

What can we conclude from this?

If a slanting plank is used to lift a weight, we have to bear less of the weight and lifting it becomes easier. Such a plank is called an ‘inclined plane’. The more gradual the slope, the lesser is the weight we bear. But such an inclined plane is longer. The steeper the slope, the shorter the inclined plane. But we have to bear a greater weight.

Two routes, namely, a pathway and a road are available to climb the mountain shown in the picture. Compare the time and strength and your convenience required to reach the mountain top.

A needle is required for stitching cloth. We use a knife for cutting fruit. If the tip of a needle or the edge of a knife becomes blunt, then the needle does not penetrate the cloth and the knife does not cut into the fruit. Why is this so?

Which tasks can be done using lever?

Some machines we use in our day-to-day life are shown in the picture. What is the type of lever in each of these?

All of you must have enjoyed sitting on a giant wheel. What makes the giant wheel go round? 

The giant wheel is fitted to a rod at its centre. This rod is called an ‘axle’. When the axle starts rotating with the help of electricity, the wheel fitted to it also starts rotating. This combination of an axle and a wheel is a simple machine. We see innumerable examples of its use. 

When the pedal of a bicycle is rotated, the wheel starts rotating. How does this happen?

Classify the following as a lever, a pulley and an inclined plane:

A wedge

Classify the following as a lever, a pulley and an inclined plane:

A needle

Classify the following as a lever, a pulley and an inclined plane:

A staircase

Classify the following as a lever, a pulley and an inclined plane:

A slide

Classify the following as a lever, a pulley and an inclined plane:

The wheel of a flagpole

Classify the following as a lever, a pulley and an inclined plane:

Nutcrackers

Classify the following as a lever, a pulley and an inclined plane:

Scissors

Classify the following as a lever, a pulley and an inclined plane:

An opener

Classify the following as a lever, a pulley and an inclined plane:

An axe

Classify the following as a lever, a pulley and an inclined plane:

A crane

Classify the following as a lever, a pulley and an inclined plane:

A knife

The ______ in the centre, the ______ on one side and the ______ on the other side make a lever of the first order.

The ______ in the centre, the ______ on one side and the ______ on the other side make a lever of the second order.

The ______ in the centre, the ______ on one side and the ______ on the other side make a lever of the third order.

Which machine will you use to do the following work? Write their type.

To remove the lid of a tin.

Which machine will you use to do the following work? Write their type.

To lift bricks to the top of a tall building.

Which machine will you use to do the following work? Write their type.

To cut vegetables.

Which machine will you use to do the following work? Write their type.

To draw water from a well.

Which machine will you use to do the following work? Write their type.

To hold a papad for roasting it.

What is meant by simple machines?

Mention the advantages of using a machine.

What is meant by complex machines?

What is a lever? 

How are the orders of the lever determined?

Why is this so traveller’s bags have wheels?

Why is this so machines have to be maintained?

Why is this so a bicycle is said to be a complex machine?

Name the levers mentioned in the following passage. Identify the fulcrum, load, and effort of each and say which type of lever it is.

Ravi and Savita sit on a seesaw in a garden. In the meantime, a gardener is trimming trees in the garden. He puts the leaves and other garbage in the wheelbarrow. Later, Ravi gets thirsty and he buys lemon sherbet. The sherbet seller cuts the lemon and squeezes it using a lemon squeezer. He puts small pieces of ice in the glass with the help of the tongs.

Make a list of the various machines used in your home and neighbourhood and write their types.

Go to a bicycle repair shop, observe how a bicycle is repaired, and note down the information.