In a lever, 120 N load is attached at a distance of 20 cm from the fulcrum. If this effort is used to lift 50 kg weight then, find

The machines which are simple in construction and help to make our work easier and faster are called simple machines.

• The ratio of the load to the effort is called the MA of a simple machine.
• A machine having 100 % efficiency is called an ideal machine. No such simple is ideal in real life.
• A lever is a rigid bar. It may be straight or bent, and it rotates about fixed points called a fulcrum.
• There are three classes of a lever based on the location of fulcrum, effort, and load.
• Pulleys are of three types, i) Fixed pulley, ii) Movable pulley, iii) Block and tackle
• The slanted surface is called an inclined plane.
• The wheel and axle are a combination of two cylinders of different diameters.
• A screw is a cylinder having spirally wounded threads around it.
• All cutting and piercing instruments are called wedges.

Physical Quantities 27 Electricity & Magnetism 48 Motion 8 Measurement 4 Electricity 166 Physical Optics 80 Waves 117 Force 51 Heat 137 Laws of Motion 1 Light 100 Pressure 139 Thermodynamics 1

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Simple Machine | Notes, and Solutions | Class 8, Science

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