Worksheet Solutions: Mechanical Projects - 3 | DIY Science Fun: Cool School Projects - Class 6 PDF Download

Fill in the Blanks

Q1: A hydraulic lift uses a __________ medium and the application of force within a piston to lift a load.
Ans: A hydraulic lift uses a liquid medium and the application of force within a piston to lift a load.
Hydraulic lifts rely on a liquid, typically hydraulic oil, as the medium to transmit force and operate the lift.

Q2: The scientific principle behind hydraulic lifts is based on __________ law.
Ans: The scientific principle behind hydraulic lifts is based on Pascal's law.
Pascal's law states that when pressure is applied to a fluid in a closed container, it is transmitted equally in all directions. This principle is fundamental to the operation of hydraulic systems, including hydraulic lifts.

Q3: Pressure is defined as the ratio of force applied perpendicularly to the __________ area.
Ans: Pressure is defined as the ratio of force applied perpendicularly to the unit area.
Pressure is indeed defined as the force applied perpendicularly to a given unit of area. It is typically measured in units such as Pascals (Pa) or pounds per square inch (psi).

Q4: Hydraulic systems utilize __________ fluids as their primary component.
Ans: Hydraulic systems utilize liquid fluids as their primary component.
Hydraulic systems primarily use liquid fluids, such as hydraulic oil, because liquids are virtually incompressible and can transmit force efficiently.

Q5: Pascal's law states that when pressure is applied to a fluid inside a closed container, the force is transmitted to both the liquid and the container's __________.
Ans: Pascal's law states that when pressure is applied to a fluid inside a closed container, the force is transmitted to both the liquid and the container's walls.
Pascal's law describes how pressure applied to a fluid is transmitted throughout the fluid and to the container's walls, ensuring that the force is evenly distributed.

Q6: In a hydraulic lift model, two __________ are used to create the lifting mechanism.
Ans: In a hydraulic lift model, two syringes are used to create the lifting mechanism.
Two syringes are typically used in a hydraulic lift model—one to act as the source of fluid to raise the load, and the other to provide a way for the fluid to return when lowering the load.

Q7: The liquid medium used in a hydraulic lift model is often represented by __________ ink.
Ans: The liquid medium used in a hydraulic lift model is often represented by colored ink.
Colored ink is commonly used in hydraulic lift models to represent the liquid medium (hydraulic oil) and make the demonstration more visually engaging.

Q8: The top part of the hydraulic lift model, where the load is placed, is typically a rectangular piece of __________.
Ans: The top part of the hydraulic lift model, where the load is placed, is typically a rectangular piece of cardboard.
The top part of the hydraulic lift model is usually made of cardboard or a similar material and serves as the platform where the load is positioned.

Q9: One of the safety precautions for building the hydraulic lift model is to wear __________ to protect your eyes.
Ans: One of the safety precautions for building the hydraulic lift model is to wear safety glasses to protect your eyes.
Safety glasses are essential to protect your eyes from potential splashes or accidents while conducting the experiment.

Q10: Removing the needle from the syringe initially is done to prevent accidental __________.
Ans:  Removing the needle from the syringe initially is done to prevent accidental pricking.
Removing the needle from the syringe before starting the experiment is a safety measure to avoid accidental needle pricks or injuries.

Multiple Choice Questions (MCQ)

Q1: What scientific principle is the hydraulic lift model based on?
(a) Boyle's law
(b) Pascal's law
(c) Newton's law of motion
(d) Archimedes' principle
Ans: (b) Pascal's law
The hydraulic lift model is based on Pascal's law, which describes how pressure is transmitted through a fluid in a closed container. This principle is fundamental to the operation of hydraulic systems.

Q2: What is the primary purpose of the tube and connector in the hydraulic lift model?
(a) To add weight to the model
(b) To connect the syringes
(c) To decorate the model
(d) To measure pressure
Ans: (b) To connect the syringes
The tube and connector in the hydraulic lift model serve the purpose of connecting the two syringes. They create a pathway for the fluid (colored ink) to flow between the syringes, allowing the lifting mechanism to function.

Q3: Which component in the hydraulic lift model acts as the lifting mechanism?
(a) The cardboard frame
(b) The top rectangular piece
(c) The syringes
(d) The colored ink
Ans: (c) The syringes
In the hydraulic lift model, the syringes act as the lifting mechanism. By pushing or pulling the fluid (colored ink), they raise or lower the load.

Q4: What is the function of the colored ink in the syringes of the hydraulic lift model?
(a) To add color for aesthetic purposes
(b) To create hydraulic pressure
(c) To cool down the model
(d) To provide lubrication
Ans: (b) To create hydraulic pressure
The colored ink in the syringes represents the hydraulic fluid. When the syringes are operated, the ink creates hydraulic pressure, which is transmitted to lift or lower the load.

Q5: Which of the following is NOT an advantage of the hydraulic lift project mentioned in the article?
(a) Enhanced understanding of scientific concepts
(b) Promotion of engagement with scientific concepts
(c) Discouragement of curiosity
(d) Valuable insights into hydraulic lifts
Ans: (c) Discouragement of curiosity
The hydraulic lift project encourages curiosity and engagement with scientific concepts, so it does not discourage curiosity. This option is incorrect as it contradicts the educational goals of the project.

True or False

Q1: Pascal's law states that when pressure is applied to a fluid inside a closed container, the force is transmitted to both the liquid and the container's walls. (True/False)
Ans: True
This statement is true. Pascal's law indeed states that pressure applied to a fluid in a closed container is transmitted throughout the fluid and to the container's walls.

Q2: Hydraulic lifts use gaseous fluids as their primary component. (True/False)
Ans: False
This statement is false. Hydraulic lifts primarily use liquid fluids, not gaseous fluids, as their primary component. Liquids are preferred due to their incompressibility.

Q3: Wearing safety glasses is not necessary when conducting the hydraulic lift experiment. (True/False)
Ans: False
This statement is false. Wearing safety glasses is necessary to protect your eyes from potential splashes or accidents while conducting the hydraulic lift experiment.

Q4: Removing the needle from the syringe initially is done to prevent accidental pricking. (True/False)
Ans: True
This statement is true. Removing the needle from the syringe before starting the experiment is a safety measure to avoid accidental needle pricks or injuries.

Q5: The hydraulic lift model is primarily built for grade 10 students. (True/False)
Ans: False
This statement is false. The hydraulic lift model is suitable for grade 6 and grade 7 students, as mentioned in the introduction. It serves as an educational tool for understanding scientific concepts.

Short Answer Questions

Q1: Explain the scientific principle behind the hydraulic lift model.
Ans: The scientific principle behind the hydraulic lift model is Pascal's law. Pascal's law states that when pressure is applied to a fluid inside a closed container, the force is transmitted equally in all directions within the fluid. In the context of the hydraulic lift model, this means that when force is applied to one syringe filled with a liquid (colored ink), the pressure is transmitted to the other syringe, causing it to move and lift a load. This principle forms the basis of hydraulic systems, including hydraulic lifts.

Q2: What is the purpose of having two syringes in the hydraulic lift model?
Ans: Having two syringes in the hydraulic lift model serves the purpose of creating a hydraulic mechanism. One syringe acts as the source of hydraulic pressure, and the other syringe provides a way for the hydraulic fluid to return when lowering the load. When force is applied to one syringe, it pushes the hydraulic fluid into the other syringe, causing it to extend and lift the load. Releasing the force allows the hydraulic fluid to flow back, lowering the load. The two syringes work together to facilitate the lifting and lowering of the load.

Q3: How does the hydraulic lift model demonstrate Pascal's law?
Ans: The hydraulic lift model demonstrates Pascal's law by showing how pressure applied to a fluid inside a closed system is transmitted uniformly throughout the fluid. When force is applied to one syringe in the model, it exerts pressure on the hydraulic fluid (colored ink) inside the syringe. According to Pascal's law, this pressure is transmitted through the fluid to the other syringe, causing it to extend and lift the load. The fluid transmits the force equally in all directions, just as Pascal's law dictates. This demonstration illustrates the fundamental principle of hydraulic systems.

Q4: List three materials required to build the hydraulic lift model.
Ans: Three materials required to build the hydraulic lift model are:

• Cardboard (various sizes): Used to create the structural components of the model.
• Syringes (two 10ml syringes): Serve as the main components of the hydraulic mechanism.
• Tube and connector: Connect the two syringes to allow the flow of hydraulic fluid between them.

 Q5: Why is it important to fill the syringes with colored ink in the model?
Ans: Filling the syringes with colored ink in the model serves several purposes:

• Visualization: Colored ink represents the hydraulic fluid in the model, allowing students to visually observe the movement of the fluid as it transfers pressure and operates the hydraulic lift.
• Engagement: The use of colored ink makes the experiment more engaging and understandable for students, as they can see the fluid's response to pressure changes.
• Demonstration: Colored ink helps in demonstrating the operation of a hydraulic system and how Pascal's law applies to it, enhancing the educational value of the model.

Q6: Describe one advantage of the hydraulic lift project mentioned in the article.
Ans: One advantage of the hydraulic lift project mentioned in the article is "Enhanced Understanding." By building and experimenting with the hydraulic lift model, students can deepen their understanding of scientific concepts related to force, pressure, hydraulic systems, Pascal's law, and more. This hands-on experience allows students to connect theoretical knowledge with practical applications, making learning more meaningful and memorable.

Q7: What safety precautions should be taken when building the hydraulic lift model?
Ans: Several safety precautions should be taken when building the hydraulic lift model, including:

• Wearing safety glasses: Safety glasses should be worn to protect the eyes from potential splashes or accidents.
• Handling the DIY knife carefully: The DIY knife is sharp and can cause cuts if mishandled, so it should be used with caution.
• Supervision: The experiment should be performed under the supervision of parents, teachers, or senior siblings to ensure safe and responsible conduct.
• Removing the needle from the syringe initially: This precaution is taken to prevent accidental pricking or injuries while handling the syringes.

 Q8: What is the role of the tube and connector in the hydraulic lift model?
Ans: The tube and connector in the hydraulic lift model serve as essential components for connecting the two syringes. Their role is to create a sealed pathway between the syringes, allowing the hydraulic fluid (colored ink) to flow from one syringe to the other. When force is applied to one syringe, it pushes the fluid into the tube, and the connector ensures that the fluid is transferred to the second syringe. This interconnected system of tubes and syringes is what enables the hydraulic mechanism to function, raising and lowering the load.

Q9: Name one everyday application of hydraulic lifts mentioned in the introduction.
Ans: One everyday application of hydraulic lifts mentioned in the introduction is "vehicles." Hydraulic lifts are commonly used in various types of vehicles, such as car lifts in automotive repair shops and hydraulic elevators in larger vehicles like buses and trucks. They allow for the efficient lifting of heavy loads with minimal force, making them crucial in automotive maintenance and transportation.

Q10: What are the potential educational benefits of building and demonstrating the hydraulic lift model in a science class?
Ans: The potential educational benefits of building and demonstrating the hydraulic lift model in a science class include:

• Enhanced Understanding: Students gain a deeper understanding of scientific concepts, including force, pressure, hydraulic systems, and Pascal's law, through hands-on experimentation.
• Practical Application: The model allows students to apply theoretical knowledge to a real-world scenario, reinforcing their learning.
• Engagement and Curiosity: The experiment motivates students to be curious and engaged with science, promoting a love for learning.
• Insight into Hydraulic Lifts: Students acquire valuable insights into how hydraulic lifts work, which can expand their knowledge of technology and engineering.
• Science Fair Opportunities: The project can serve as an exciting and informative idea for science fairs, fostering creativity and presentation skills.