The pulley in the jib of a crane has a diameter of 56cm. Find:
a) The circumference of the pulley
b) The number of revolutions turned by the pulley when the crane raises a load through a vertical height of 44m.
C = pi * d
so, the turns is 44/C
where C is in meters
To find the circumference of the pulley, you can use the formula:
Circumference = π * Diameter
a) Circumference = π * 56 cm
b) To find the number of revolutions, we need to determine the length of the rope that the pulley moves when the crane raises the load. This length can be calculated using the formula:
Length = Vertical Height
The number of revolutions can be found by dividing the length by the circumference of the pulley. Therefore:
Number of revolutions = Length / Circumference
Given that the vertical height is 44 m, we need to convert it to centimeters to match the units of the circumference, which is centimeters.
Vertical Height (in cm) = 44 m * 100 cm/m
Now, we can substitute the values into the equation:
Number of revolutions = (Vertical Height (in cm)) / (Circumference)
Calculate the value of the circumference and the vertical height, and then divide the vertical height by the circumference to find the number of revolutions.