An electric motor operates at 939 watts, which is 85% of the input. What is the input in watts?
Answer (2)
Let x represent the input in watts.
Set up the equation: 0.85 x = 939 .
Solve for x : x = 0.85 939 ≈ 1104.71 .
The input in watts is approximately 1104.71 watts.
Explanation
Setting up the equation Let x be the input in watts. We know that 85% of the input is 939 watts. We can write this as an equation: 0.85 x = 939
Isolating x To solve for x , we need to divide both sides of the equation by 0.85: x = 0.85 939
Calculating x Now, we perform the division to find the value of x : x = 1104.7058823529412 Rounding to two decimal places, we get: x ≈ 1104.71
Final Answer Therefore, the input in watts is approximately 1104.71 watts.
Examples
Understanding percentages and proportions is crucial in many real-life situations. For example, when calculating discounts while shopping, determining the percentage of ingredients in a recipe, or figuring out the efficiency of machines. In this case, knowing the input power of an electric motor helps in assessing its energy consumption and efficiency, which is important for managing energy costs and ensuring optimal performance. If a motor's output is 939 watts and it's 85% efficient, calculating the input power helps determine how much energy is being used, allowing for informed decisions about energy-saving measures.
To find the input power of the motor, we set the equation 0.85 x = 939 and solve for x to determine that the input is approximately 1104.71 watts. This helps in assessing the motor's energy efficiency.
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