By using a pulley system, a farmer makes it easier to lift bales of hay by reducing the force needed. The energy she uses to complete the task is 10,000 joules, and the work done on the bales of hay is 8,000 joules. What was her efficiency in this task? (1 point)
Responses
18,000 joules
125%
80%
2,000 joules
Efficiency is calculated as (useful work output / total energy input) x 100%. In this scenario, the useful work output is 8,000 joules and the total energy input is 10,000 joules. Therefore, efficiency is (8,000 / 10,000) x 100% = 80%.
The answer is 80%.
To find the efficiency, we need to divide the useful output work by the total input energy and multiply by 100 to express it as a percentage.
Efficiency = (useful output work / total input energy) * 100
In this case, the useful output work is given as 8,000 joules, and the total input energy is given as 10,000 joules.
Efficiency = (8,000 / 10,000) * 100 = 80%
Therefore, her efficiency in this task is 80%.
To find the efficiency of the task, we need to determine the ratio of the work done to the energy used. Efficiency is calculated using the following formula:
Efficiency = (useful output energy / input energy) x 100%
In this case, the useful output energy is the work done on the bales of hay, which is 8,000 joules. The input energy is the energy used by the farmer, which is 10,000 joules.
Efficiency = (8,000 joules / 10,000 joules) x 100%
Simplifying the ratio:
Efficiency = 0.8 x 100% = 80%
So, the farmer's efficiency in this task is 80%, which means 80% of the energy used by the farmer was effectively used to do the work on the bales of hay.