Earth, whose in situ weight is 105 lb/cf and whose compacted weight is 122 lb/cf, is placed in a fill at the rate of 260 cy/hr, measured as compacted earth. the thickness of the compacted layers is 7 in. a compactor with a roller drum width of 4.16 ft is used to compact the material at a speed of 2 mph. assume a 55-min hour operating efficiency. determine the number of rollers.

2

Explanation:

To find the solution we must first make the transformations to international units,

In this way:

Inches of length (L) to feet =

So we can identify the area by hour:

Once the area is identified, we now identify the number of passes required,

Passes required = Area x number of passes

We transform speed to international units

So we can identify the covered area

where

m = drum widht

p = efficiency

In this way we obtain the number of rollers given by:

No. of Rollers = Passes required / covered area

No of rollers = 48136/40269

No of rollers = 1.19, that is, 2.

Number of rollers required are 2.

at positions a, g kinetic energy is maximum.

at position d, potential energy is maximum.

here we know that ball will drop down by total distance 3.2 m

so here we know that

now using kinematics

now in the same time it will cover horizontal distance of 0.75 m

so speed of the ball will be