Question

Difficulty: MediumSimple Machines

A machine with a velocity ratio of 66 is used to raise a load of 540 N540\text{ N} by applying an effort of 120 N120\text{ N}. What is the efficiency of the machine?

  1. 75%75\%Answer
  2. B
    133.3%133.3\%
  3. C
    22.2%22.2\%
  4. D
    450%450\%

Answer

The efficiency of the machine is 75%75\%.
The correct option is 75%75\%. Mechanical Advantage is found by dividing the load (540 N540\text{ N}) by the effort (120 N120\text{ N}), giving 4.54.5. Dividing this mechanical advantage by the given velocity ratio (66) and expressing as a percentage yields 4.56×100%=75%\frac{4.5}{6} \times 100\% = 75\%.

Step-by-Step Solution

1
Calculate Mechanical Advantage (MA)
MA=LoadEffort=540 N120 N=4.5\text{MA} = \frac{\text{Load}}{\text{Effort}} = \frac{540\text{ N}}{120\text{ N}} = 4.5
Mechanical advantage measures the force magnification produced by the machine.
2
CalculateEfficiency(η)Calculate Efficiency (\eta)
η=(MAVR)×100%=(4.56)×100%=75%\eta = \left(\frac{\text{MA}}{\text{VR}}\right) \times 100\% = \left(\frac{4.5}{6}\right) \times 100\% = 75\%
Efficiency is the ratio of Mechanical Advantage to Velocity Ratio multiplied by 100%.

Key Concept

Efficiency of a Simple Machine
Estimated Time:1m 0s
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