Pulleys

Principle: A Pulley is a wheel with a groove along its edge for holding a rope or cable or belt. Pulleys are used to change the direction of an applied force, transmit rotational motion, or realize a mechanical advantage in either a linear or rotational system of motion.

Applications: These are used in lifts, cranes, elevators, conveyer belts and in other machines. It is also used in building construction for reducing the effort.

Items Required to make:
Pulleys (two)
A stand for supporting the pulleys
Thread

Things To Know: Types of pulleys

1. A fixed or class 1 pulley has a fixed axle. It is used to change the direction of the force on a rope.

2. A movable or class 2 pulley has a free axle. A movable pulley is used to multiply forces.

3. A compound pulley is a combination of fixed and movable pulley system.
Block and tackle - A block and tackle is a compound pulley where several pulleys are mounted on each axle, further increasing the mechanical advantage.o

The effort applied to pull the load is decreased as the number of pulley's increases. But the system is less efficient due to the friction in the system where cable meets pulley and in the rotational mechanism of each pulley

Dynamo

Principle: A coil being rotated between the magnets generates an EMF at its ends
Dynamo works on the principle of conversion of mechanical energy into electrical energy

Applications:
Wind mills, turbines, use the same principle to generate electricity

Items Required to make:
Dynamo Model

Things To Know:
Dynamo Windmill is an example of dynamo which works on the same principle of conversion of mechanical energy into electrical energy. For this mechanical energy is wind energy.