Tamilnadu Samacheer Kalvi 4th Science Solutions Term 1 Chapter 3 Work and Energy

 

Tamilnadu Samacheer Kalvi 4th Science Solutions Term 1 Chapter 3 Work and Energy

Samacheer Kalvi 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

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Question 3.
___________ is a machine made up of wheel and rope. 

Answer: Pulley

Question 4.
____________ help us to make work easier.
Answer: Simple machines

Question 5.
An example for inclined plane is ____________.

Answer: Ramp

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II. Rearrange the letters and find out the names of the tools :

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                                                WEDGE           LEVER                  SCREW

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III. Match.

1. Class II lever   - Drawing water

2. Pulley   - Bicycle

3. Class I lever   - Nut cracker

4. Wheel and axle   - Wind

5. Renewable resource - Seesaw

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III. Match.

1. Class II lever   - Nut cracker

2. Pulley   - Drawing water

3. Class I lever   - Seesaw

4. Wheel and axle   - Bicycle

5. Renewable resource   - Wind

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IV. Classify the things below : (Text Book Page No. 109)

Question 1.

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V. Answer the following :

Question 1.
What is the unit of energy?

Answer:
The S.I. Unit of energy is the joule.

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Question 2.
Name some simple machines.

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

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Question 3.
What is a first order lever?

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

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Question 4.
Lemon juicer belongs to which type of lever? Why?

Answer:
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.

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Question 5.
Define work.

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

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Question 6.
Write any three types of energy.

Answer:

Mechanical energy.

Thermal energy.

Chemical energy.

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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.

Question 1.

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Let us do (Text Book Page No. 104)

Mention whether work is done or not in the following activity.

Question 1.

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Try to Answer (Text Book Page No. 109)

Identify and mention the types of simple machines.

Question 1.

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Let us do (Text Book Page No. 109)

Complete the table.

Question 1.

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Try to Answer (Text Book Page No. 111)

Name the load, effort and fulcrum.
Question 1.

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