PULLEYS AND LIFTING - QUESTIONS 1
V. Ryan © 2004 - 2017
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1a. A simple pulley system is shown opposite. A 40N effort is used to move a 80N load. The final effort moves 2 metres and at the same time the load moves 1 metre. |
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1b. Work out the efficiency of the pulley system. |
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It is important to remember that NO pulley system is 100% efficient. This is due to friction of the ropes against the pulley wheels and the friction of the bearings of the pulley wheels as they rotate. 100% efficiency is only theoretical.. |
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The calculations for example 2 are seen below. This type of pulley arrangement will always have the same mechanical advantage and velocity ratio. |
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