2.  A pulley system that is linked with a belt is called belt drive.  A lot of machines works with belt drive for example, motorcars and escalators.  If the Driver pulley turns, it moves the belt and the driven pulley will turn. Belt drive is an example of how pulleys can bring over turning motion.

3.  Like gears, pulleys can increase or lower the torque and speed of the driven pulley.  By measuring the diameter of the pulleys in the pulley system, you can determine the speed ratio with the formula we use at gears.

4.  SPEED RATIO = DIAMETER OF DRIVEN PULLEY/ DIAMETER OF THE DRIVING PULLEY

5.  By using the diameter of the pulleys in the diagram you can determine the speed ratio:  Speed ratio = Diameter of driven pulley / diameter of driving pulley  Speed Ratio = 0.3m / 0.1m  Speed ratio = 3:1

6.  This means that every time the driver pulley turns 3 times, the driven pulley will turn 1 time.  Thus the Torque of the driven pulley is increased.

7.  Pulley systems change the direction of turning motion. You can change the turning motion by bringing torsion to the cable.

8.  Advantages and Disadvantages of Pulley systems.

9.  Pulleys and gears have similar functions. A person that wants to create a machine can use a pulley system or gear system depending on the purpose of the machine.  Pulley system is quieter and more easier to make, but doesn’t handle well when a big torque is needed.  Pulleys can be used over greater distances, where gears must be closer to each other.  Gears can handle bigger load, but more difficult to make.

10.  One of the problems with belt drive is when the load gets too big the cable will slip.  One way to overcome this problem is to use a chain and gear pulley system. The driven and driver pulleys have teeth like gears.

11.  A Chain fits in the teeth of the pulleys. When the drive pulley turns, the cable turns and it drives the driven pulley.  These pulleys ensure that the cable doesn’t slip.

12.  A Chain and gear pulley system is used in bicycles.  Cyclists must bring the turning of pedals to a high torque to the bicycle wheel.  the cyclist is pedaling, the smaller driver pulley turns. The wheel is mounted on a bigger driven pulley. Because the driven pulley is bigger than the driver pulley, the driven pulley has more torque. It assures that the cyclist can move up the mountain easier.

13. 1. What Formula can be used to determine the Speed ratio of a belt drive? 2. What does Speed ratio mean? 3. A Belt drive has a speed ratio of 5:1. What does that mean? 4. A Belt drive has a speed ratio of 1:3. What does that mean?

14.  5. A Belt drive is set up. The diameter of the driver pulley is 20 cm. The diameter of the driven pulley is 60 cm. 1. Determine the speed ratio of this belt drive. 2. Does the belt drive have a big torque.  6. Draw the diagrams to show the different ways to how belt drive can be used to change the turning motion.  7. Draw a diagram to show how a chain and gear pulley system can prevent a pulley system from slipping.