Machines became part of our daily lives. They help us to do work easily. Scissors, brakes, pulley, hears, screw jack etc. all are examples of machines. Machines help us to reduce efforts required to do the work. They have few or no moving parts. These machines uses energy to do work. A simple machine is a mechanical device that changes the direction or magnitude of a force. In this chapter, we are going to study six simple machines. All big complicated machines are based on the combination of these simple machines. To increase the efficiency of our work, we need to reduce friction. We will also learn about friction and lubrication in this lesson.
After going this lesson, you will be able to:
- define the prinicples of simple machine
- define different types of simple machines
- explain the concept of friction and lubrication