Final answer:
The power generated by a machine that lifts a 120kg load through a height of 2m in 30s, with an efficiency of 100%, and assuming g=10m/s², is 80 W.
Step-by-step explanation:
To calculate the power generated by the machine, we need to use the formula for power, which is the rate of doing work.
The work done by the machine in lifting the load is given by the gravitational potential energy (GPE) formula:
Work (W) = mass (m) × gravity (g) × height (h). Using the given values:
W = 120kg × 10m/s² × 2m = 2400 J (joules).
Since the machine has an efficiency of 100%, all this work is useful work.
The power (P) generated by the machine is the work done per unit of time.
Therefore, Power (P) = Work (W) / time (t).
Plugging the values in, we get: P = 2400 J / 30 s = 80 W (watts).