Effect of friction on the efficiency

This experimental study investigates the effect of friction on the efficiency of a pulley \nsystem. Efficiency of systems is affected by problems like friction, which is also a major problem \nfor energy consumption in the world. In a pulley system consisting of an electric motor, fixed \npulleys and a load; “Does changing the number of pulleys in a pulley system affect friction and \nhence efficiency of the system to alter?” question is tested. The experiment was made in two parts. \nFirst, revolutions per minute (rev/min – rpm) pattern of the electric motor was plotted on a graph. \nAfter deciding the voltage for second part, the effect of friction on the efficiency of the pulley \nsystems was investigated. For that, the number of pulleys attached to the system was increased step \nby step and how high (meters) the 0.1 kg mass is pulled in 1 minute time by the electric motor is \nmeasured. Comparing theoretical height and measured height values gave the energy loss at the \nsystem. According to the law of conservation of energy that loss should be due to the effect of \nfriction. So, the efficiency of the system was calculated using the data gathered. The results were \nplotted on a graph and they showed that as the number of pulleys in the system increases from 1 \nblue pulley to 5 black & 5 blue pulleys step by step, the efficiency of the system decreases from \n99.598 % to 96.185 %. Those results show that increasing number of pulleys in a pulley system \naffects friction to increase and hence efficiency of the system to decrease.