‘Machines’ Physics Project (ICSE Class X)

Physics Project for Machines for ICSE Class X students.

Project Structure: Introduction, Machine, Functions and uses of simple machines, technical terms related to machines, principle of machine, levers, kinds of levers, pulley, conclusion, bibliography.

Introduction

A machine is a mechanical structure that uses power to apply forces nd control movement to perform an intended action. Machines can be driven by animals and people, by natural forces such as wind and water, and by chemical, thermal or electrical power and include a system of mechanisms that shape the actuator input to achieve a specific application of output forces and movement. They can also include computers and sensors that monitor performance and plan movement, often called mechanical systems. In this project, we will take a look at machines, pulley, types of pulleys, levers, types of levers, etc.

A machine is a devise than can either overcome a large resistance force (or load) at some point by applying a small force (or effort) at a convenient point and in a desired direction or by which we can obtain a gain in speed.

Functions and Uses of Simple Machines

1) In lifting a heavy load by applying the less effort i.e. as a force multiplier.

Examples: A jack is used to lift a car, a bar is used to left a heavy stone, a spade is used to churn the soil, pulleys are used to carry a load, a wheel barrow is used to carry a load. In all these examples, the effort applied is much less than the load, so the machines acts as a force multiplier.

2) In changing the point of application of effort to a convenient point.

Example: The rear wheel of a cycle is rotated by applying the effort on the pedal attached to the toothed wheel which is joined to the real wheel. with the help of a chain. Thus the point of application is changed from the pedal to the rear wheel.

3) In changing the direction of effort to a convenient direction.

Example: In a well for lifting water.

4) For obtaining a gain in speed.

Example: Scissors.

Technical Terms Related to Machine

Load

The resistive or opposing force to be overcome by a machine is called the Load (L).

Effort

The force applied on the machine to overcome by a machine load is called Effort (E).

Mechanical Advantage (M.A)

The ratio of the load to the effort is called the Mechanical advantage of the machine.

Mechanical Advantage (M.A) = Load (L) / Effort (E)

Unit: It has no unit.

Velocity Ratio (V.R)

The ratio of the velocity of effort to the velocity of load is called the velocity ratio of machine i.e.

Velocity Ratio (V.R) = Velocity of Effort (Ve) / Velocity of Load (VL)

Unit: It has no unit.

Work Input

The work done on the machine by the effort, is called the work input (Winput), i.e.

Work input = Work done by the effort

Work Output

The work done on the machine on load, is called the work output (Woutput), i.e.

Work output = Work done on the load

Efficiency

Efficiency of a machine is the ratio of the work done on load by the machine to the work done on machine by the effort.

In other words, efficiency is the ratio of the work output to the work input. It is denoted by the symbol η (eta).

Efficiency η = Work Output (Woutput) / Work Input (Winput) x 100

Unit: It has no unit.