a labourer lifts 100 stone to a height of 6m in two minute.if mass of each stone be one kilogram, calculate the average power ( gravity = 10ms-² )
P = m g h / t = 100 * 10 * 6 / 120
answer is in Watts
To calculate the average power, we need to first find the work done by the laborer and then divide it by the time taken.
The work done is given by the formula: work = force × distance
In this case, the force is equal to the weight of each stone, and the distance is the height the stones are lifted.
Since the mass of each stone is given as 1 kilogram and the gravity is given as 10 m/s², we can calculate the weight of each stone using the formula: weight = mass × gravity
Weight = 1 kg × 10 m/s² = 10 N (Newtons)
The total work done can be calculated by multiplying the weight of the stones by the distance they are lifted: work = weight × distance
Work = 10 N × 6 m = 60 N·m (Newtons times meters)
Now, since the laborer lifts 100 stones, the total work done would be the work done by one stone multiplied by 100: total work = work per stone × number of stones
Total work = 60 N·m × 100 = 6000 N·m
Finally, we need to divide the total work by the time taken to find the average power: average power = total work ÷ time
Since the time given is 2 minutes, we need to convert it to seconds: time = 2 minutes × 60 seconds/minute = 120 seconds
Average power = 6000 N·m ÷ 120 seconds = 50 N·m/s
Therefore, the average power is 50 N·m/s.