Answer:
W = 0
Explanation:
We are given with, a construction worker is carrying a load of 40 kg over his head and is walking at a constant velocity. He travels a distance of 50 m.
The work done by an object is given by :
F = ma
So,
m is mass
a is acceleration
d is displacement
The worker is moving with constant velocity, its acceleration will be 0. So, the work done by the worker is 0.
Answer:
P = 251,916.667 W
Cost = 2,267.25 cents
Explanation:
To solve this question we will use the Work Energy Theorem, which is
Where
= Change in Potential Energy
= Change in Kinetic Energy
Change in Potential Energy
Where
= Initial Potential Energy
= Final Potential Energy
= Mass of System = 10,000 kg
= Acceleration due to gravity = 9.81 m/s
= Initial Height = 0
= Final Height = 30 m
Inputting the values we get the answer for
Change in Kinetic Energy
Where
= Initial Kinetic Energy
= Final Kinetic Energy
= Mass of System = 10,000 kg
= Acceleration due to gravity = 9.81 m/s
= Initial Velocity = 0 m/2
= Final Velocity = 4 m/s
Inputting the values we get the answer for
Total Work
Inputting the values
a) Finding the useful Power Output
Where
= Power Output
= Work Done = 3,023,000J
= Time = 12s
Inputting the values
P = 251,916.667 W
b) Finding the Total Cost
Cost = $0.0900 x P/1000
Cost = $0.0900 x (251,916.667/1000)
Cost = $22.67 or 2,267.25 cents