Key Principles Behind Making a Physics Lifter and Real-World Applications
Do you know what is a lifter? A lifter is something that carries heavy loads. It works on the principle of Pascal’s law. A simple lifter is a hydraulic lifter and is one of the commonly known lifters.
You must have observed a balloon and an airplane flying even if there’s a weight difference. So, what lifts them up? Also, you might’ve seen a lifter in service centres and garages. You feel enthusiastic to build the same device.
If you are the one looking for an effortless and interesting technique to build the same, keep scrolling this page.
How to Make a Lifter?
In making a lifter, we will use the following household items:
Cardboard for listing
Fevicol
0.8 inch round table (2.032 cm)
Scissors
Steps to Make a Lifter
Cut an indexed board wider by 1/3rd, while keeping the longer side the same size as that of the object to be lifted. A lifer with a width of 0.25 inches and a length of 1 inch would be enough for a 0.75 round table.
Now, fold the strip of paper to make it of the shape of an alphabet ‘N’
Apply fevicol on one side of the paper lifter and attach the end with the fevicol cover against the backend of the diagram where the picture would be placed for raising.
Now, attach the label to another part of the lifter of paper. If the object attached does not possess a label with a sticky part, try using fevicol to secure it at the lifter end.
Concept of a Lift
Let’s hold a spoon in one hand and a balloon in the other. Release your hands and you observe that the balloon rises up and the spoon falls. Similarly, if you take a pan of millions of spoons and consider an airplane. The airplane flies while spoons remain as such. So, why is there a difference between these two scenarios?
Well, in a balloon and an airplane, there’s something called Dynamic lift that lifts these two up.
In an airplane, four types of forces are acting on it, the lower one is weight, the upper one is a lift, the forward force is thrust and the backward is a drag.
When the engine’s thrust pushes the airplane forward, the drag pulls it backwards and when the lift pulls it up, the weight of an airplane pulls it down. Since the pressure at the upper end, is higher and that at the lower side is low, this pressure difference between the two ends creates an effective upward force, which is a dynamic lift that lifts the plane up.
So this was the case for an object flying in the sky. Now, let’s discuss what do hydraulic lifters do?
What is a Hydraulic Lifter?
A hydraulic lifter is of two types viz: hydraulic flat tappet lifter and hydraulic roller lifter. A flat lifter looks flat at the bottom and the roller lifter comprises rollers at the bottom, as you can see in two images below:
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Flat lifter Roller lifter
A roller lifter is greater in height than a flat lifter. A roller is preferred to a flat lifter in the following ways:
Though it is costly, i.e., about 7-8 mn dollars but it produces more horsepower than the standard or a flat lifter.
Rollers at the bottom produce less friction because when they roll on the camshaft, there’s no resistance, so more durability of lifters.
A hydraulic lifter works on the phenomenon of Pascal’s law. You can see a simple diagram of a hydraulic lifter below:
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This hydraulic lift is found in service centres, where servicemen lift the car up for repairing. Here, you can see two cylinders connected to each other with a pipe. These two cylinders bear differing cross-sectional areas and each of these is provided with an airtight frictionless piston.
Let A1, A2 be the cross-sectional areas of two pistons held at the top of these two cylinders, respectively, where A2 >> A1, as we can see that the piston on the left-hand side bears a smaller area as compared to that on the right-hand side.
(Image to be added soon)
Now, these cylinders are filled with an incompressible liquid, as you can in the image below:
(Image to be added soon)
The downward force applied on the left piston is F1 and the pressure exerted on it is:
P = F1/A1
Now, according to Pascal’s law, this pressure is equally transmitted to the small piston of the cylinder on the RHS, so the pressure exerted on it will be:
P = Fg/A2
Since A2 >> A1, therefore Fg > F1.
It means that the force applied to the smaller piston appears as a very large force on the large one. As a result of this heavy load like a car or a motorbike placed on the larger piston is easily lifted upwards.
FAQs on How to Make a Lifter in Physics: Detailed Steps Explained
1. What is a lifter in the context of physics?
A lifter is a device designed to raise or support heavy objects using a mechanical advantage. In physics, the term most often refers to systems that apply fundamental principles like Pascal's Law (for hydraulic lifters) or Bernoulli's principle (for aerodynamic lift, like on an airplane wing). These devices multiply a small input force to generate a much larger output force.
2. What is the basic principle behind a hydraulic lifter?
A hydraulic lifter operates on Pascal's Law. This principle states that pressure applied to an enclosed, incompressible fluid is transmitted undiminished to every portion of the fluid and the walls of the containing vessel. In a hydraulic lift, a small force applied to a small piston creates pressure, which is then transmitted to a larger piston, generating a large enough force to lift a heavy load.
3. How can you make a simple model of a lifter at home?
You can create a simple mechanical pop-up lifter using basic materials to understand the concept of a mechanism. Here are the steps:
- Cut a strip of sturdy cardboard or paper.
- Fold the strip into an 'N' or accordion shape. This will act as the lifting mechanism.
- Attach one end of the folded strip to a base (e.g., a page in a book).
- Attach the object you want to lift (like a paper cutout) to the other end of the 'N' shape.
4. Why can a small force applied to a hydraulic lift raise a very heavy object like a car?
This is possible due to the relationship between force, pressure, and area (P = F/A). A small force (F1) is applied to a piston with a small area (A1), creating pressure (P) in the hydraulic fluid. According to Pascal's Law, this pressure is transmitted equally to a larger piston with a much larger area (A2). The resulting upward force on the larger piston (F2) is the product of this pressure and the larger area (F2 = P * A2). Since A2 is much greater than A1, the output force F2 becomes significantly larger than the input force F1, allowing it to lift a heavy object like a car.
5. What is the difference between the 'dynamic lift' for an airplane and the lift from a hydraulic system?
The key difference lies in the underlying physics principle.
- Dynamic Lift (Airplanes): This is generated based on Bernoulli's principle. The curved shape of an airplane's wing causes air to travel faster over the top surface than the bottom. This speed difference creates lower pressure on top and higher pressure below, resulting in a net upward force called lift.
- Hydraulic Lift: This is generated based on Pascal's Law. It uses an enclosed, incompressible fluid to transmit pressure from a small piston to a large piston, thereby multiplying force. It does not depend on fluid motion or aerodynamics.
6. How does the shape of an airplane's wing help in generating lift?
The cross-sectional shape of an airplane wing, known as an airfoil, is crucial for generating lift. It is designed to be curved on the top and flatter on the bottom. As the wing moves through the air, this shape forces the air flowing over the top to travel a longer distance—and therefore move faster—than the air flowing underneath. According to Bernoulli's principle, faster-moving air exerts lower pressure. This pressure difference between the lower (high pressure) and upper (low pressure) surfaces of the wing creates a net upward force, which is the aerodynamic lift.
7. Are all lifters based on hydraulics? What are some other examples?
No, not all lifters are based on hydraulics. While hydraulic systems are common for heavy-duty applications, lifters can operate on various principles. Other examples include:
- Mechanical Lifters: These use simple machines like levers, pulleys (cranes), or screw jacks to gain a mechanical advantage.
- Pneumatic Lifters: Similar to hydraulic lifters, but they use a compressible gas like air instead of an incompressible liquid to transmit pressure.
- Electromagnetic Lifters: These use powerful electromagnets to lift and move ferromagnetic materials, common in scrap yards and steel mills.
8. What role does the incompressibility of the fluid play in a hydraulic lifter's function?
The incompressibility of the fluid (usually oil) is a fundamental requirement for a hydraulic lifter to work efficiently. Because the fluid cannot be easily compressed, any force applied to the input piston instantly translates into work done on the output piston. If the fluid were compressible (like a gas), the initial force would be wasted on squeezing the fluid itself, leading to a significant loss of energy and a delay in the lifting action. Incompressibility ensures that pressure is transmitted directly and undiminished as per Pascal's Law.
