# 4th Science Guide Term 1 Lesson 3

## 4th Science Solutions Term 1 Chapter 3 Work and Energy

4th Standard Science Term 1 Lesson 3 Work and Energy Book Back Question and Answers Download PDf. 4th Science Term 1 English Medium Book in answers. 4th All Subject Book Back Answers

## 4th Science Guide Work and Energy Text Book Back Questions and Answers

### I. Use the correct word to fill the blanks :

(Ramp, Simple machines, Work, Energy, Pulley)

1. ___________ is said to be done when a force is acting on it.Answer:Work

#### Question 2.

The ability to do work is __________.Answer:Energy

#### Question 4.

____________ help us to make work easier.Answer:Simple machines

#### Question 5.

An example for inclined plane is ____________.Answer:Ramp

### V. Answer the following :

#### What is the unit of energy?

• The S.I. Unit of energy is the joule.

#### Name some simple machines.

• Simple machines are pulley, wedge, inclined plane, screw, lever, wheel and axle.

#### What is a first order lever?

• When the fulcrum is between the effort and the load, it is known as Class I lever.
• Example: scissors, pliers, seesaw.

#### Lemon juicer belongs to which type of lever? Why?

• Lemon juicer belongs to Class II Lever. In a lemon squeezer, the lemon (load) is at the middle, the load is at the center of effort and fulcrum.

#### Define work.

• An action in which one exerts a force to move an object is known as work.

#### Write any three types of energy.

• Mechanical energy.
• Thermal energy.
• Chemical energy.

## Samacheer Kalvi 4th Science Guide Work and Energy In Text Questions and Answers

### Try to Answer (Text Book Page No. 104)

Observe the picture and put a tick ✓) if work is done and put a cross (x) if work is not done.

### Try to Answer (Text Book Page No. 111)

Name the load, effort and fulcrum.

## Samacheer Kalvi 4th Science Guide Work and Energy Additional Questions and Answers

### I. Pick out the odd one :

#### Question 1.

Mechanical energy, Heat energy, Chemical energy, Food

#### Question 2.

Scissors, broomstick, wrench, sea saw

#### Question 3.

petrol, coal, natural gas, water.

### II. Say true or false :

#### Question 1.

Chemical energy is one of the types of lever.

#### Question 2.

Simple machines usually exchange a larger force to move a heavy object.

#### Question 3.

The idea of a simple machine originated with the Greek philosopher Archimedes.

#### Question 4.

A lever is used to multiply the force.

1. (b)
2. (a)
3. (d)
4. (c)

### IV. Choose the correct answer :

#### second order lever ___________.

(a) Scissors

(b) lemon squeezer

(c) Tongs

#### Which of the following device converts chemical energy into electrical energy?

(a) Battery

(b) Loud speaker

(c) Solar cell

(d) Electric motor

(a) Sun

(b) Wind

(c) Water

(d) Petrol

(a) Joule

(b) kilogram

(c) Mass

(d) Watt

#### A is a push or a pull

(a)Force

(b)Friction

(c) Simple machine

(d) pulley

(a) Motion

(b) Work

(c) Friction

(d) Distance

#### A force can cause an object to change its

(a) Shape

(b) Speed

(c) Direction

(d) All the above

### V. Fill in the blanks :

#### Question 1.

A ___________ should act on an object.Answer:Water

#### Question 3.

_____________ is used to split materials.Answer:Wedge

#### Question 4.

The screw is used to raise _____________.Answer:Weights

### VI. Answer the following questions in one or two sentences :

#### What is non-renewable resources?

The resources which are not easily replaced once used are called the non renewable resources.

Example: Petrol, Coal and Natural gas.

#### Question 2.

• Renewable sources of energy are replaced naturally over a period of time.
• We can keep using these sources for a long period of time. Since the beginning of human life, we have been using these resources.
• We use these resources for light, transport, cooking, heating. Eg: Sun, Wind and Water.

#### Write the two main conditions are needed for work to be done?

Two main conditions are needed for work to be done.

1. A force should act on an object.
2. Object should move from one place to another.

#### What is work?

An action in which one exerts a force to move an object is known as work.

#### Define energy?

• Energy is defined as capacity for doing work.
• Energy must be transferred to an object in order to do work.

#### Write the type of energy.

• Mechanical energy.
• Thermal energy
• Chemical energy
• Electrical energy
• Non-renewable energy
• Renewable energy

#### What is simple machine?

• Simple machines are tools which are used to make our work easier.
• Some examples for simple machines are pulley, wedge, inclined plane,