Did you know?
Did you know that the efficiency of a machine is a measure of how much useful work it can actually perform? In this case, with an efficiency of 80%, it means that 80% of the energy input into the machine is converted into useful work.
Now, let's calculate the work done by a person using this machine to raise a load of 300kg through a height of 4m. To do this, we can use the equation:
Work = Efficiency x Energy Input
First, we need to calculate the energy input. Energy is defined as the product of mass, gravitational acceleration, and height. Given that the load is 300kg and gravitational acceleration (g) is 10 m/s^2, the energy input is:
Energy Input = Mass x g x Height
= 300 kg x 10 m/s^2 x 4 m
= 12,000 kg•m^2/s^2
Now, using the efficiency of 80% (or 0.8 in decimal form), we can calculate the work done:
Work = Efficiency x Energy Input
= 0.8 x 12,000 kg•m^2/s^2
= 9,600 kg•m^2/s^2
Therefore, the work done by a person using the machine to raise the load of 300kg through a height of 4m is 9,600 kg•m^2/s^2. Keep in mind that this value represents the useful work output, as 80% efficiency filters out the remaining energy as waste or non-useful work.