With the help of a stationary block, a load weighing 50 kg is lifted to a height of 12 m
With the help of a stationary block, a load weighing 50 kg is lifted to a height of 12 m, while a force of 600N acts. Define useful work, total work and efficiency
Given:
m = 50 kilograms – the mass of the load, which is lifted using a fixed block;
h = 12 meters – the height to which the load is lifted;
F = 600 Newton – the force with which the load is lifted.
It is required to determine A1 (Joule) – useful work, A2 (Joule) – full work and n – engine efficiency.
The useful work will be equal to the potential energy of the load:
A1 = m * g * h, where g = 10 Newton / kilogram (approximate value;
A1 = 50 * 10 * 12 = 500 * 12 = 6000 Joules.
The total work expended will be equal to:
A2 = F * h = 600 * 12 = 7200 Joules.
The efficiency will be equal to:
n = A1 / A2 = 6000/7200 = 0.83 = 83%.
Answer: the useful work is 6000 Joules, the total work is 7200 Joules, the efficiency of the unit is 83%.