Question

The power expended in lifting an 825-lb girder to the top of a building 100 ft high
is 10.0 hp. How much time is required to raise the girde

Answer 1

r to the top of the building?
First, we need to convert the power from horsepower to watts. 1 horsepower is equal to 746 watts.
So, 10.0 hp = 10.0 x 746 = 7460 watts.
Next, we calculate the work done in lifting the girder to the top of the building. Work = force x distance.
Force = weight = 825 lb and distance = 100 ft.
Converting the weight to force in Newtons:
1 lb = 4.448 N
825 lb = 825 x 4.448 = 3666 N
Work = 3666 N x 100 ft = 366600 N*ft = 366600 Joules
Now, we can calculate the time required using the formula:
Power = Work/Time
Time = Work/Power
Time = 366600 J / 7460 watts = 49.15 seconds
Therefore, the time required to raise the girder to the top of the building is approximately 49.15 seconds.