The diagram above illustrates a block ans tackle pulley system in which an effort E supports a load of 100.0N. If the efficiency of the machine is 75%, calculate the value of E
A. 22.2N B. 38.0N C. 67.0N D. 75.0N
Correct Answer: A
Explanation
Given; VR = 6, e = 75%, MA = ? e = \(\frac{\text{MA}}{\text{VR}} \times \frac{100}{1}\) MA =\(\frac{75 \times 6}{10}\) MA = \(\frac{9}{2}\) MA = \(\frac{L}{E} = \frac{100}{E}\) \(\frac{9}{2} = \frac{100}{E}\) 9E = 100 E = \(\frac{200}{9}\) = 22.2N
