Work and Energy

What is force?

Force means to push or pull something.

Which other two actions have been mentioned that require force?

To stop something and to change the direction also requires force

ØQ1. How was force applied on the balloon?

Blowing with the mouth so the shape of the balloon changed.

ØQ2. How was force applied on the table and chair?

Table was pushed and pulled, chair was lifted.

ØReinforce the definition of force

–Force is a push or a pull. It can change the direction of a moving object.It can stop a moving object.It can also change the shape of an object

Q4.In the above actions did the objects on which force was being applied show any movement

or change its shape?

Yes when we apply force on an object and there is movement of object then it is said that some work has been done. Today we will learn what is work and when can we say that work is done.Work is said to be done only if the force exerted on an object moves that object form its position. i.e there is displacement of the object.

Give some examples of work where the object moves from its position?

(pushing a trolley, stitching, carrying things etc.)

Why do we eat food?

(Because it gives us energy)

What does the word solar mean?

Solar means the energy related to the Sun

ØWhat are the things that are important for us to survive on earth.

(air,water, food and light)

ØHow the sunlight is helpful to the plants.(it helps them to grow and toprepare food)

Photosynthesis isthe process by which green plants use carbon dioxide in the air and water

and minerals from the soil to produce their own food in the presence of sunlight. Sunlight is absorbed with the help of chlorophyll, a green pigment present in the leaves. The food prepared by the leaf is stored in different parts of the plant and oxygen gas is given out in the process

Hence it is not only helpful to plants and animals but to all the living creatures on the earth

he rainwater that is stored in the dam is used as a source of energy to produce electricity.

The water is held behind a dam, forming an artificial lake, or reservoir. The water is released from the dam which spins the blades of a giant turbine. The turbine is connected to the generator that makes electricity as it spins.This energy is also called hydro energy.

1. What do we do to regain our lost energy?

Eat the right kind of food and rest enough.

Ø

What food is the right kind of food?A balanced diet.

ØDo we eat them raw?

Some are eaten raw while some are cooked.

ØWhat are the different methods of cooking?

Boiling, roasting, frying steaming.

ØWhat is the important thing required

for cooking?

Cooking gas

ØDo people in the rural areas also use gasfor cooking?

No, they burn wood.

ØWhat does the blue colour on the globe denote?

The part of the earth covered with water.

ØHow much of the earth is covered with water?

Three fourth of the earth is covered with water.

the heat generated from the earth is called geothermal energy

ØWhy do we need these batteries?For the functioning of all battery operated things.

ØWhat do we do when a battery operated toy or a watch stops

working?

We change the battery.

Ø

What do we do when our mobile screen or laptop screen goes blank

at the end of the day?

We recharge it using batteries

Øthat all battery operated things will stop working because they

function with the energy stored in the batteries.

Øthat batteries store energy in them which can be utilized whenever

we need energy to make use of things that are battery operated.

(if possible show the different types of batteries)