What is a Lever?

In A simple machine consisting of a rigid bar pivoted on a fixed point and used to transmit force, as in raising or moving a weight at one end by pushing down on the other.

In physics a lever is a rigid object that is used with an appropriate fulcrum or pivot point to multiply the mechanical force (effort) that can be applied to another object (load). Lever is one of the six simple mechanics. Products such as lever support, lever clamp and lever stick are used to teach, learn and demonstrate the fundamental concepts of lever, moments, and mechanical advantage.

For demonstration of levers and related experiments or calculations, the lever clamps are mounted on two opposite ends of the lever stick and the location of fulcrum or pivot point is changed until a balance is reached.

Lever Clamp (Knife Edge Clamp) order/pricing

Lever clamp is a dual function device that can be used as a pivot point and to hang the load and effort forces. Lever clamp has an opening for inserting the lever stick. Lever stick can easily slide into the opening and it can be secured at any location using a thumb screw on the top of the lever clamp. Each lever clamp has two side arms used as pivot point to hold the lever on any standard lever stand or lever support. The same arms can also support a wire hanger used to hang the load or effort forces. The wire hanger can be removed for when you use the lever clamp as pivot point.

Lever Stick

Lever stick is a long wooden stick made of hardwood and is graduated in millimeters, centimeters and decimeters.  Lever stick is 25 mm wide and 5 mm thick. Lever sticks are available in 50 cm and 100 cm lengths.

Lever Support (Lever Stand)

Lever supports are are available in two different types. Either one is good for all lever related experiments; however, the cast metal lever support is taller.

Cast Lever Support order/pricing

The cast lever support stands 18.5 cm tall. Made of aluminum alloy, it has a small foot print and a single piece structure that contributes to its durability.

The base is about 7 cm x 8 cm.

There are two groves on the top for supporting knife-edge lever clamp.

It weighs 220 grams.

Traditional Lever Support order/pricing

The traditional lever support stands 13 cm tall. It has a heavy cast iron base with nickel plated steel columns.

The base is about 9 centimeter in diameter.

It weighs about 450 grams.

How to select a lever support?

Choice are a heavy short fulcrum or a light tall fulcrum. The wire hangers on a lever clamp plus a tall weight with hook require about 14 cm space. So 13 cm height will not be enough. The shot/ heavy lever stand is only recommended when you are using short weights or you are hanging the weights directly to the lever stick. Otherwise the taller lever stand is a safer choice.

Lever Demonstration Set

A lever demonstration set includes all you need to assemble a basic lever for demonstration. You will also need weights with hooks, weight hangers with slotted weights or spring scales to complete your demonstration or experiments. This set includes a lever support, 3 lever clamps and one lever stick or meter stick.

While ordering you will get the choice of 100 centimeter stick or 50 cm stick.

Lever demonstration set may be used to show the principles of levers, torque or moment and mechanical advantage.

The image on the left shows how a lever set along with a 100-gram weight and a 500-gram weight are used to demonstrate the action of a lever system. The 100-gram weight is fully in balance with the 500-gram weight.

This is another creative idea using a lever demonstration set. By hanging two lids from metal cans this set is converted to a balance scale.

Balance scales and levers are very similar. As a matter of fact many balance scales known as bench scales or platform scales use the lever system for measuring heavy weights.

Teaching the mechanics of Levers.

Start by talking about what a lever does in order to create some interest and excitement about the subject. Tell them that they can easily lift a car alone with the help of levers. Or they can lift their friend with the push of one finger.

Then explain the parts of a lever such as Fulcrum and a long solid object. In the classroom you will use a lever support as a fulcrum and a lever stick as the solid object. If you wanted to show more practical applications or lifting a person with one finger, then you can by a 6 feet long 2 x 4 pine wood and a of break. The advantage of using a lever stick is the ability to read distances and calculate the torque and mechanical advantage.

Torque is the force that causes an item to rotate. Torque is calculated in "Newton meter" or "pound-feet".

To calculate the torque or moment, multiply the force by its distance from the fulcrum.

The mechanical advantage (MA) of a lever is the factor by which a lever multiplies the force put into it. For example if you use 1 Lb force to lift a 15 Lb object, then the mechanical advantage will be 15.