Grade IV worksheet on Force, Work and Energy with questions on gravity, work, energy conversion, and simple machines.

Problem Analysis:

The task involves filling in blanks, unscrambling words to identify machines and their types, and defining key terms related to force, work, and energy. Let's solve each part step by step.

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Part 1: Fill in the blanks

#### a. "Everything that has a ______ is pulled towards the Earth due to gravity."
- Explanation: Gravity acts on objects with mass. The blank should be filled with the term that describes this property.
- Answer: Mass

#### b. "______ is said to be done when an object moves to some distance as a result of force acting on it."
- Explanation: Work is defined as the product of force and displacement when the force acts in the direction of motion.
- Answer: Work

#### c. "When a tube light is switched on, it converts the ______ energy into ______ energy."
- Explanation: A tube light (fluorescent lamp) converts electrical energy into light energy when it is turned on.
- Answer: Electrical → Light

#### d. "The energy released by splitting the atoms is called ______."
- Explanation: Splitting atoms releases nuclear energy, which is a form of energy derived from nuclear reactions.
- Answer: Nuclear energy

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Part 2: Unscramble the following to write the names of different machines. Also, write the type of simple machine they belong to.

#### a. LAIN
- Unscrambled Word: Nail
- Type of Machine: Wedge (A nail is a type of wedge used to split or hold materials together.)

#### b. FEIKK
- Unscrambled Word: Kite
- Type of Machine: None (A kite is not a simple machine; it is a device for flying in the air using wind power.)

#### c. RKOF
- Unscrambled Word: Fork
- Type of Machine: Wedge (A fork has prongs that act like wedges to pierce or hold food.)

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Part 3: Define

#### a. Force
- Definition: Force is a push or pull upon an object resulting from the object's interaction with another object. It is measured in Newtons (N) and can cause an object to accelerate, decelerate, or change its shape.

#### b. Friction
- Definition: Friction is the resistive force that opposes the relative motion or tendency of such motion of two surfaces in contact. It depends on the nature of the surfaces and the normal force between them.

#### c. Simple Machines
- Definition: Simple machines are devices that change the magnitude or direction of a force to make work easier. They include levers, pulleys, inclined planes, wedges, screws, and wheels and axles.

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Final Answer

1. Fill in the blanks:
- a. Mass
- b. Work
- c. Electrical → Light
- d. Nuclear energy

2. Unscramble the words:
- a. Nail → Wedge
- b. Kite → None
- c. Fork → Wedge

3. Definitions:
- a. Force: A push or pull upon an object resulting from the object's interaction with another object.
- b. Friction: The resistive force that opposes the relative motion or tendency of such motion of two surfaces in contact.
- c. Simple Machines: Devices that change the magnitude or direction of a force to make work easier.

Boxed Final Answer:
\[
\boxed{
\text{1. a. Mass, b. Work, c. Electrical → Light, d. Nuclear energy} \\
\text{2. a. Nail → Wedge, b. Kite → None, c. Fork → Wedge} \\
\text{3. a. Force: A push or pull, b. Friction: Resistive force, c. Simple Machines: Devices to make work easier}
}
\]